View MAX34462EXQ_8869564.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

general description the max34462 is a system monitor that can manage up to 16 power supplies. the power-supply manager monitors the power-supply output voltages and con - stantly checks for user-programmable overvoltage and undervoltage thresholds. if a fault is detected, the device automatically shuts down the system in an orderly fash - ion. the device can sequence the supplies in any order at both power-up and power-down. the device contains 16 independent voltages dacs, which the device uses to close-loop margin the power-supply output voltages up or down to a user-programmable level. the device contains an internal temperature sensor and can support up to four external remote temperature sensors. once configured, the device can operate autonomously without any host intervention. applications network switches/routers base stations servers smart grid network systems beneits and features 16 channels of power-supply management power-supply voltage or current measurement and monitoring fast minimum/maximum threshold excursion detection differential input sensing improves measurement accuracy 16 independent voltage dacs for power-supply margining automatic closed-loop margining programmable up and down sequencing up to four independent sequencing loops 5v tolerant power-supply output enables internal temperature sensor reports peak and average levels for a number of parameters pmbus?-compliant command interface i 2 c/smbus-compatible serial bus with bus timeout function on-board nonvolatile black box fault logging and default configuration setting expandable channel operation with parallel devices sequencing can be timing synchronized across multiple devices configurable combinatorial logic supporting up to 16 gpis and 36 gpos no external clocking required +3.0 to +3.6v supply voltage ordering information and typical operating circuit appear at end of data sheet. for related parts and recommended products to use with this part, refer to www.maximintegrated.com/max34462.related . pmbus is a trademark of smif, inc. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs 19-6785; rev 0; 9/13 evaluation kit available downloaded from: http:///
max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 2 table of contents general description ............................................................................ 1 applications .................................................................................. 1 benefits and features .......................................................................... 1 absolute maximum ratings ...................................................................... 8 recommended operating conditions .............................................................. 8 electrical characteristics ........................................................................ 9 i 2 c/smbus interface electrical specifications ....................................................... 11 i 2 c/smbus timing ............................................................................. 11 typical operating characteristics ................................................................ 12 bump configuration ........................................................................... 14 bump description ............................................................................. 15 expanded bump description ................................................... ............... 20 csbga bump map ................................................... ....................... 20 block diagram ............................................................................... 21 detailed description ........................................................................... 22 pmbus/smbus address select ................................................... ............. 26 smbus/pmbus operation ................................................... .................. 26 smbus/pmbus operation examples ................................................... ....... 27 group command ................................................... ......................... 28 group command write format ................................................... ........... 28 addressing ................................................... ............................. 28 alert and alert response address (ara) ................................................... ... 28 host sends or reads too few bits ................................................... .......... 28 host sends or reads too few bytes ................................................... ......... 29 host sends too many bytes or bits ................................................... .......... 29 host reads too many bytes or bits ................................................... .......... 29 host sends improperly set read bit in the slave address byte ....................................... 29 unsupported command code received/host writes to a rea d-only command ......................... 29 invalid data received ................................................... ..................... 29 host reads from a write-only command .................................................. ...... 29 smbus timeout ................................................... .......................... 29 pmbus operation ................................................... ........................ 29 pmbus protocol support ................................................... .................. 30 data format ................................................... ............................ 31 interpreting received direct format values ................................................... .. 31 sending a direct format value ................................................... ............ 31 fault management and reporting ................................................... ........... 31 downloaded from: http:///
max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 3 table of contents ( continued) password protection ................................................... ...................... 32 power-supply sequencing ................................................... ................. 32 quad-loop sequencing .................................................. .................... 33 power-on sequencing ................................................... .................. 34 power-off sequencing ................................................... .................. 34 sequencing example ................................................... ................... 34 multiple device connections .................................................. ................ 35 seq pin operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 sync pin operation ................................................... ...................... 37 system watchdog timer ................................................... ................... 37 crc memory check ................................................... ...................... 37 pmbus commands ........................................................................... 37 page (00h) ................................................... ............................. 37 operation (01h) ................................................... ....................... 39 on_off_config (02h) ................................................... ................... 41 clear_faults (03h) ................................................... .................... 42 write_protect (10h) ................................................... .................. 42 device configuration data management ................................................... ...... 42 store_default_all (11h) ................................................... ............... 43 restore_default_all (12h) ................................................... ............ 43 mfr _store_ all (eeh) ................................................... .................. 44 mfr_restore_all (efh) ................................................... ............... 44 mfr_store_single (fch) ................................................... .............. 44 mfr_crc (feh) ................................................... ......................... 45 capability (19h) ................................................... ....................... 45 vout_mode (20h) .................................................. ....................... 45 vout_command (21h) ................................................... .................. 45 vout_margin_high (25h) ................................................... ............... 46 vout_margin_low (26h) ................................................... ............... 46 vout_scale_monitor (2ah) ................................................... ............ 46 iout_cal_gain (38h) ................................................... .................... 47 vout_ov_fault_limit (40h) ................................................... ............. 47 vout_ov_warn_limit (42h) ................................................... ............. 47 vout_uv_warn_limit (43h) ................................................... ............. 47 vout_uv_fault_limit (44h) ................................................... ............. 47 iout_oc_warn_limit (46h) ................................................... .............. 47 iout_oc_fault_limit (4ah) ................................................... .............. 48 ot_fault_limit (4fh) .................................................. .................... 48 downloaded from: http:///
max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 4 table of contents ( continued) ot_warn_limit (51h) ................................................... ................... 48 power_good_on (5eh) ................................................... ................ 48 power_good_off (5fh) ................................................... ................ 48 ton_delay (60h) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 toff_delay (64h) .................................................. ....................... 48 ton_max_fault_limit (62h) ................................................... ............. 49 status_word (79h) ................................................... .................... 49 status_vout (7ah) ................................................... ..................... 51 status_iout (7bh) ................................................... ..................... 51 status_temperature (7dh) .................................................. ............. 51 status_cml (7eh) ................................................... ...................... 52 status_mfr_specific (80h) ................................................... ............ 52 read_vout (8bh) ................................................... ....................... 53 read_iout (8ch) .................................................. ........................ 53 read_temperature_1 (8dh) ................................................... ............ 53 pmbus_revision (98h) ................................................... .................. 53 mfr _id (99h) ................................................... ........................... 53 mfr_model (9ah) ................................................... ...................... 53 mfr_revision (9bh) ................................................... .................... 53 mfr_location (9ch) ................................................... ................... 53 mfr _ date (9dh) ................................................... ........................ 54 mfr_serial (9eh) ................................................... ...................... 54 mfr_mode (d1h) .................................................. ........................ 54 mfr_psen_config (d2h) ................................................... ............... 55 delay function ................................................... .......................... 56 mfr_vout_peak (d4h) ................................................... .................. 57 mfr_iout_peak (d5h) ................................................... .................. 57 mfr_temperature_peak (d6h) ................................................... ......... 57 mfr_vout_min (d7h) ................................................... ................... 57 mfr_iout_avg (e2h) ................................................... .................... 57 mfr_nv_log_config (d8h) ................................................... ............. 57 mfr_fault_response (d9h) ................................................... ............ 58 local vs. global channels .................................................. ............ 58 global channels respond to fault assertion ............................................... 59 temperature fault response ................................................... ............. 59 fault detection before power-on sequencing .................................................. 59 logging faults into mfr_nv_fault_log ................................................... . 59 alarm output functionality ................................................... .............. 62 downloaded from: http:///
max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 5 table of contents ( continued) mfr_fault_retry (dah) ................................................... ................ 63 mfr_nv_fault_log (dch) ................................................... .............. 63 mfr_time_count (ddh) ................................................... ................ 65 mfr_channel_config (e4h) ................................................... ............ 65 mfr_ton_seq_max (e6h) ................................................... ............... 68 mfr_seq_config (e8h) ................................................... ................. 68 mfr_dac_config (e9h) ................................................... ................. 68 delay function ................................................... .......................... 71 mfr_margin_config (dfh) ................................................... ............. 71 power-supply margining operation .................................................. ........ 71 margining faults ................................................... ....................... 72 dac value ................................................... ........................... 72 dac margining component selection ................................................... ...... 72 temperature sensor operation ................................................... ............. 72 mfr_temp_sensor_config (f0h) ................................................... ....... 73 mfr_gpo_config (f8h) ................................................... ................. 73 delay function ................................................... .......................... 75 applications information ........................................................................ 75 dvdd, avdd, vref, and reg18 decoupling ................................................... .. 75 open-drain pins .................................................. ......................... 75 keep-alive circuit ................................................... ....................... 75 configuration port ................................................... ....................... 75 resistor-dividers and source impedance for rs inputs ............................................. 75 protecting input pins ................................................... ...................... 75 typical operating circuit ....................................................................... 76 ordering information .......................................................................... 77 package information .......................................................................... 77 revision history .............................................................................. 78 downloaded from: http:///
max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 6 list of figures list of tables figure 1. pmbus/smbus address select .......................................................... 26 figure 2. sequence control logic ................................................................ 33 figure 3. sequencing example .................................................................. 35 figure 4. multiple max34462 hardware connections ................................................ 36 figure 5. on_off_config logical control ........................................................ 41 figure 6. device configuration data management ................................................... 42 figure 7. status register organization ............................................................ 50 figure 8. mfr_psen_config functional logic .................................................... 56 figure 9. input to output delay action ............................................................. 56 figure 10. mfr_fault_response operation .................................................... 61 figure 11. mfr_nv_fault_log ................................................................ 63 figure 12. mfr_channel_config command .................................................... 67 figure 13. mfr_dac_config functional logic .................................................... 71 figure 14. margining hardware configurations ..................................................... 72 figure 15. mfr_gpo_config functional logic .................................................... 75 table 1. pmbus page to pin/resource mapping .................................................... 22 table 2. device channel capabilities and options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 table 3. pmbus command codes ................................................................ 23 table 4. pmbus/smbus serial port address ........................................................ 26 table 5. pmbus command code coefficients ...................................................... 30 table 6. coefficients for direct format value ..................................................... 31 table 7. fault-monitoring states ................................................................. 32 table 8. operation command sequence control options ........................................... 33 table 9. page (00h) commands ................................................................. 38 table 10. operation (01h) command byte with page = 0 to 15 (when bit 3 of on_off_config = 1) ...... 39 table 11. operation (01h) command byte with page = 255 (when bit 3 of on_off_config = 1) ......... 40 table 12. operation (01h) command byte (when bit 3 of on_off_config = 0) ....................... 40 table 13. on_off_config (02h) command byte ................................................... 41 table 14. write_protect (10h) command byte .................................................. 42 table 15. memory transfer pmbus commands ..................................................... 43 table 16. mfr_crc (feh) command byte ........................................................ 45 table 17. capability (19h) command byte ....................................................... 45 table 18. vout_scale_monitor (2ah) examples ................................................ 46 table 19. status_word (79h) ................................................................. 49 downloaded from: http:///
max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 7 list of tables ( continued) table 20. status_vout (7ah) ................................................................. 51 table 21. status_iout (7bh) .................................................................. 51 table 22. status_temperature (7dh) ......................................................... 51 table 23. status_cml (7eh) .................................................................. 52 table 24. status_mfr_specific (80h) (for pages 0 to 15) ......................................... 52 table 25. status_mfr_specific (80h) (for page 255) ............................................ 53 table 26. mfr_mode (d1h) .................................................................... 54 table 27. mfr_psen_config (d2h) ............................................................ 55 table 28. mfr_nv_log_config (d8h) .......................................................... 57 table 29. fault-monitoring states ................................................................ 59 table 30. mfr_fault_response (d9h) ......................................................... 60 table 31. alarm_config codes ............................................................... 61 table 32. mfr_fault_response codes for global channel s ..................................... 62 table 33. mfr_fault_response codes for local channel s ...................................... 62 table 34. mfr_nv_fault_log (dch) ........................................................... 64 table 35. mfr_channel_config (e4h) ........................................................ 66 table 36. mfr_seq_config (e8h) ............................................................. 69 table 37. mfr_dac_config (e9h) .............................................................. 70 table 38. mfr_margin_config (dfh) .......................................................... 71 table 39. ds75lv address pin configuration ....................................................... 73 table 40. mfr_temp_sensor_config (f0h) .................................................... 73 table 41. gpo description ...................................................................... 73 table 42. mfr_gpo_config (f8h) .............................................................. 74 downloaded from: http:///
dvdd/avdd to dvss/avss ............................... -0.3v to +4.0v rsn/gpin to avss .............................................. -0.3v to +0.3v psen to dvss ..................................................... -0.3v to +5.5v all other pins (except reg18 and reg18a) relative to dvss/avss ..... -0.3v to (v dvdd /v avdd + 0.3v)* reg18 and reg18a to avss ............................. -0.3v to +2.0v continuous power dissipation (t a = +70oc) csbga (derate 40mw/oc above +70oc) .................. 2200mw operating temperature range ............................ -40oc to +95oc storage temperature range ............................. -55oc to +125oc soldering temperature (reflow) ....................................... +260oc *subject to not exceeding +4.0v. (t a = -40oc to +95oc, unless otherwise noted.) parameter symbol conditions min typ max units operating voltage range v dvdd , v avdd (note 1) 3.0 3.6 v v dd rise time from 0 to 2.5v 4 ms v dd source impedance 10 input logic 1 (except i 2 c and gpi pins) v ih1 0.7 x v dd v dd + 0.3 v input logic 0 (except i 2 c and gpi pins) v il1 -0.3 +0.3 x v dd v input logic 1: scl, sda, mscl, msda v ih2 2.1 v dd + 0.3 v input logic 0: scl, sda, mscl, msda v il2 -0.3 +0.8 v input logic 1 (gpi pins) v ih3 minimum pulse width = 5ms 1.5 v dd + 0.3 v input logic 0 (gpi pins) v il3 minimum pulse width = 5ms -0.3 +1.0 v source impedance to rs adc_time[1:0] = 00 1 k adc_time[1:0] = 01 5 adc_time[1:0] = 10 10 adc_time[1:0] = 11 20 dac output capacitance load in series with > 5k 50 nf max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 8 absolute maximum ratings stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. these are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. exposure to absolute maximum rating conditions for extended periods may affect device reliability. recommended operating conditions downloaded from: http:///
(v dvdd and v avdd = 3.0v to 3.6v, t a = -40oc to +95oc, unless otherwise noted. typical values are at v dvdd /v avdd = 3.3v, t a = +25oc.) parameter symbol conditions min typ max units general supply current i cpu (note 2) 13 ma i program 16 system clock error f err:mosc +25c < t a < +95c -3 +3 % -40c < t a < 25c -4 +4 output logic-low (except i 2 c pins) v ol1 i ol = 4ma (note 1) 0.4 v output logic-high (except i 2 c pins) v oh1 i oh = -2ma (note 1) v dvdd - 0.5 v output logic-low: scl, sda, mscl, msda v ol2 i ol = 4ma (note 1) 0.4 v scl, sda, mscl, msda leakage il i2c v dvdd = 0v or loat 5 a control0 threshold 2.048 v control0 hysteresis 50 mv adcadc bit resolution 12 bits adc conversion time adc_time[1:0] = 00 1000 ns adc full scale v fs t a = 0c to +95c 2.032 2.048 2.064 v adc measurement resolution v lsb 500 v rs input capacitance c rs 15 pf rs input leakage il rs 0v < v rs < v avdd 0.25 a adc integral nonlinearity inl 1 lsb adc differential nonlinearity dnl 1 lsb dac dac resolution 8 bits dac full-scale accuracy 0c t a +95c 2.0 2.048 2.1 v dac integral nonlinearity 2 lsb dac differential nonlinearity 1 lsb dac offset error 25 mv dac load regulation dac ldreg500 v dacout > 200mv, 500a sink and source -8 +8 mv dac ldreg200 v dacout > 100mv, 200a sink and source -5 +5 output short circuit 5 ma output leakage output disabled 1 a max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 9 electrical characteristics downloaded from: http:///
(v dvdd and v avdd = 3.0v to 3.6v, t a = -40oc to +95oc, unless otherwise noted. typical values are at v dvdd /v avdd = 3.3v, t a = +25oc.) note 1: all voltages are reference to ground. currents entering the ic are specified as positive and currents exiting the ic are negative. note 2: this does not include pin input/output currents. note 3: guaranteed by design. note 4: the round-robin threshold excursion rate can be changed with the adc_average and adc_time bits in m fr_mode from 16s (no averaging and 1s conversion) to 1024s (8x averaging and 8s conversion). parameter symbol conditions min typ max units temperature sensor internal temperature measurement error t a = -40c to +95c 2 c flash flash endurance n flash (note 3) 20,000 write cycles data retention t a = +50c (note 3) 100 years store_default_all mfr_store_all write time 85 ms mfr_store_single write time 310 s restore_default_all mfr_restore_all time with mfr_store_single data 110 ms without mfr_store_single data 1.2 mfr_nv_fault_log write time writing one fault log 11 ms mfr_nv_fault_log delete time deleting all fault logs 200 ms mfr_nv_fault_log overwrite time 40 ms timing operating characteristics round-robin voltage and current sample rate threshold excursion (note 4) 64 s data collection 5 ms temperature sample rate 1000 ms device startup time with mfr_store_single data 170 ms without mfr_store_single data 90 sync clock frequency 20 khz max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 10 electrical characteristics (continued) downloaded from: http:///
(v dvdd and v avdd = 3.0v to 3.6v, t a = -40oc to +95oc, unless otherwise noted. typical values are at v dvdd /v avdd = 3.3v, t a = +25oc.) parameter symbol conditions min typ max units scl clock frequency f scl 10 400 khz mscl clock frequency f mscl 100 khz bus free time between stop and start conditions t buf 1.3 s hold time (repeated) start condition t hd:sta 0.6 s low period of scl t low 1.3 s high period of scl t high 0.6 s data hold time t hd:dat receive 0 ns transmit 300 data set-up time t su:dat 100 ns start set-up time t su:sta 0.6 s sda and scl rise time t r 300 ns sda and scl fall time t f 300 ns stop set-up time t su:sto 0.6 s clock low timeout t to 25 27 35 ms sclnote: timing is referenced to v il(max) and v ih(min) . sda stop start repeated start t buf t hd:sta t hd:dat t su:dat t su:sto t hd:sta t sp t su:sta t high t r t f t low max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 11 i 2 c/smbus interface electrical speciications i 2 c/smbus timing downloaded from: http:///
(v dvdd and v avdd = 3.3v and t a = +25c, without mfr_store_single data, unless otherwise noted.) supply current vs. temperature max34462 toc01 temperature (c) i dd (ma) 80 60 -20 0 20 40 10.5 11.0 11.5 12.0 12.5 13.0 13.5 14.010.0 -40 100 max34462 toc03 10ms/div ton_delay = 0ms ton_delay = 5ms v dd 2v/div psen0 5v/div psen1 5v/div the psenn pins power up in ahigh-impedance state. the psen pins are pulled to +5v. the controln pin is assertedwhen power is applied active- low psen active- high psen psen outputs during power-up supply current vs. supply voltage max34462 toc02 v dd (v) i dd (ma) 3.5 3.1 3.2 3.3 3.4 10.5 11.0 11.5 12.0 12.5 13.0 13.5 14.010.0 3.0 3.6 t a = +85c t a = +25c t a = -40c max34462 toc04 10ms/div v dd 2v/div fault0 2v/div fault1 2v/div fault pins during power-up max34462 toc05 20ms/div v dd gpo 2v/div pg alarm force gpo assertion pg operation alarm operation gpo output pins during power-up all pin configured to be push-pull active-high max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs maxim integrated 12 www.maximintegrated.com typical operating characteristics downloaded from: http:///
(v dvdd and v avdd = 3.3v and t a = +25c, without mfr_store_single data, unless otherwise noted.) max34462 toc06 1ms/div v dd 1v/div alert alert pin during power-up max34462 toc08 40ms/div 100mv/div dac margining voltage vs. time max34462 toc07 1ms/div v dd 1v/div rst rst pin during power-up max34462 toc09 4ms/div 5ma/div 0ma i dd faultn 2v/div i dd vs. time during a nonvolatile log write max34462 toc10 4ms/div 5ma/div 0ma i dd faultn 2v/div i dd vs. time during a nonvolatile log write with overwrite enabled max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs maxim integrated 13 www.maximintegrated.com typical operating characteristics (continued) downloaded from: http:///
top view + csbga rsp0/ gpip0 max34462 rsn0/ gpin0 dac7/ gpo23 rsp12/ gpip12 rsp13/ gpip13 reg18a dac4/ gpo20 avdd dac2/ gpo18 dac0/ gpo16 rsn1/ gpin1 rsp1/ gpip1 dac15 rsn12/ gpin12 rsn13/ gpin13 dvss dac5/ gpo21 avss dac1/ gpo17 dvdd rsn2/ gpin2 rsp2/ gpip2 avss dac13 dac14 rst dac6/ gpo22 dac3/ gpo19 mscl msda rsn3/ gpin3 rsp3/ gpip3 dac10/ gpo26 dac12 dac11/ gpo27 sync/ gpo35 dac8/ gpo24 seq/ gpo32 sda scl rsp4/ gpip4 rsn4/ gpin4 gpo33 avdd dac9/ gpo25 gpo34 dvss psen7/ gpo7 psen5/ gpo5 addr rsp5/ gpip5 rsn5/ gpin5 dvdd vref avdd psen6/ gpo6 psen10/ gpo10 psen3/ gpo3 psen1/ gpo1 psen4/ gpo4 rsp6/ gpip6 rsn6/ gpin6 reg18 avss ctrl0 psen2/ gpo2 psen13/ gpo13 dvss dvdd psen0/ gpo0 rsp7/ gpip7 rsn7/ gpin7 psen8/ gpo8 rsp11/ gpip11 rsn11/ gpin11 alert psen12/ gpo12 psen15/ gpo15 ctrl2 fault3/ gpo31 rsp8/ gpip8 rsn8/ gpin8 rsn15/ gpin15 rsn10/ gpin10 rsn14/ gpin14 fault2/ gpo30 psen11/ gpo11 psen14/ gpo14 ctrl3 fault0/ gpo28 rsp9/ gpip9 rsn9/ gpin9 rsp15/ gpip15 rsp10/ gpip10 rsp14/ gpip14 fault1/ gpo29 dvss psen9/ gpo9 ctrl1 dvss 1 2 5 3 4 6 7 10 8 9 ab c d e f g h j k max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 14 bump coniguration downloaded from: http:///
bump name type function a1 rsp0 ai adc voltage sense positive input 0. connect to avss if unused. gpip0 ai general-purpose positive input 0. connect to avss if unused. a2 rsn0 ai adc voltage sense negative input 0. connect to avss if unused. gpin0 ai general-purpose negative input 0. connect to avss if unused. b2 rsp1 ai adc voltage sense positive input 1. connect to avss if unused. gpip1 ai general-purpose positive input 1. connect to avss if unused. b1 rsn1 ai adc voltage sense negative input 1. connect to avss if unused. gpin1 ai general-purpose negative input 1. connect to avss if unused. c2 rsp2 ai adc voltage sense positive input 2. connect to avss if unused. gpip2 ai general-purpose positive input 2. connect to avss if unused. c1 rsn2 ai adc voltage sense negative input 2. connect to avss if unused. gpin2 ai general-purpose negative input 2. connect to avss if unused. d2 rsp3 ai adc voltage sense positive input 3. connect to avss if unused. gpip3 ai general-purpose positive input 3. connect to avss if unused. d1 rsn3 ai adc voltage sense negative input 3. connect to avss if unused. gpin3 ai general-purpose negative input 3. connect to avss if unused. e1 rsp4 ai adc voltage sense positive input 4. connect to avss if unused. gpip4 ai general-purpose positive input 4. connect to avss if unused. e2 rsn4 ai adc voltage sense negative input 4. connect to avss if unused. gpin4 ai general-purpose negative input 4. connect to avss if unused. f1 rsp5 ai adc voltage sense positive input 5. connect to avss if unused. gpip5 ai general-purpose positive input 5. connect to avss if unused. f2 rsn5 ai adc voltage sense negative input 5. connect to avss if unused. gpin5 ai general-purpose negative input 5. connect to avss if unused. g1 rsp6 ai adc voltage sense positive input 6. connect to avss if unused. gpip6 ai general-purpose positive input 6. connect to avss if unused. g2 rsn6 ai adc voltage sense negative input 6. connect to avss if unused. gpin6 ai general-purpose negative input 6. connect to avss if unused. h1 rsp7 ai adc voltage sense positive input 7. connect to avss if unused. gpip7 ai general-purpose positive input 7. connect to avss if unused. h2 rsn7 ai adc voltage sense negative input 7. connect to avss if unused. gpin7 ai general-purpose negative input 7. connect to avss if unused. j1 rsp8 ai adc voltage sense positive input 8. connect to avss if unused. gpip8 ai general-purpose positive input 8. connect to avss if unused. j2 rsn8 ai adc voltage sense negative input 8. connect to avss if unused. gpin8 ai general-purpose negative input 8. connect to avss if unused. k1 rsp9 ai adc voltage sense positive input 9. connect to avss if unused. gpip9 ai general-purpose positive input 9. connect to avss if unused. k2 rsn9 ai adc voltage sense negative input 9. connect to avss if unused. gpin9 ai general-purpose negative input 9. connect to avss if unused. k3 rsp10 ai adc voltage sense positive input 10. connect to avss if unused. gpip10 ai general-purpose positive input 10. connect to avss if unused. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 15 bump description downloaded from: http:///
bump name type function j3 rsn10 ai adc voltage sense negative input 10. connect to avss if unused. gpin10 ai general-purpose negative input 10. connect to avss if unused. h3 rsp11 ai adc voltage sense positive input 11. connect to avss if unused. gpip11 ai general-purpose positive input 11. connect to avss if unused. h4 rsn11 ai adc voltage sense negative input 11. connect to avss if unused. gpin11 ai general-purpose negative input 11. connect to avss if unused. a3 rsp12 ai adc voltage sense positive input 12. connect to avss if unused. gpip12 ai general-purpose positive input 12. connect to avss if unused. b3 rsn12 ai adc voltage sense negative input 12. connect to avss if unused. gpin12 ai general-purpose negative input 12. connect to avss if unused. a4 rsp13 ai adc voltage sense positive input 13. connect to avss if unused. gpip13 ai general-purpose positive input 13. connect to avss if unused. b4 rsn13 ai adc voltage sense negative input 13. connect to avss if unused. gpin13 ai general-purpose negative input 13. connect to avss if unused. k4 rsp14 ai adc voltage sense positive input 14. connect to avss if unused. gpip14 ai general-purpose positive input 14. connect to avss if unused. j4 rsn14 ai adc voltage sense negative input 14. connect to avss if unused. gpin14 ai general-purpose negative input 14. connect to avss if unused. k5 rsp15 ai adc voltage sense positive input 15. connect to avss if unused. gpip15 ai general-purpose positive input 15. connect to avss if unused. j5 rsn15 ai adc voltage sense negative input 15. connect to avss if unused. gpin15 ai general-purpose negative input 15. connect to avss if unused. c10 rst dio reset active-low input/output. contains an internal pullup. g4 control0 ai power-supply master on/off control input 0. active-low or active-high based on on_off_config command. connect to avss if unused. a series 100 resistor is recommended if this input can be driven when the device is powered down. k8 control1 di power-supply master on/off control input 1. active-low or active-high based on on_off_config command. connect to dvss if unused. a series 100 resistor is recommended if this input can be driven when the device is powered down. h8 control2 di power-supply master on/off control input 2. active-low or active-high based on on_off_config command. connect to dvss if unused. a series 100 resistor is recommended if this input can be driven when the device is powered down. j8 control3 di power-supply master on/off control input 3. active-low or active-high based on on_off_config command. connect to dvss if unused. a series 100 resistor is recommended if this input can be driven when the device is powered down. e5 gpo33 do general-purpose output 33. function is selected using the mfr_gpo_config command. d7 seq dio sequencing input/output. open-drain, active low. this pin is used as handshake signal to coordinate event-based sequencing in systems using multiple devices. gpo32 do general-purpose output 32. function is selected using the mfr_gpo_config command. d8 sda dio i 2 c/smbus-compatible input/output. open-drain output. d9 scl dio i 2 c/smbus-compatible clock input/output. open-drain output. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 16 bump description (continued) downloaded from: http:///
bump name type function c8 mscl dio master i 2 c clock input/output. open-drain output. c9 msda dio master i 2 c data input/output. open-drain output. h10 alert do alert output. open-drain, active-low output. e9 addr di smbus slave address select. this pin is sampled on device power-up to determine the smbus address. see the section on pmbus/smbus address select for details on how to strap this pin to select the proper slave address. e10 gpo34 do general-purpose output 34. function is selected using the mfr_gpo_config command. j9 fault0 dio fault input/output 0. open-drain, active-low. see the expanded bump description section for more details. gpo28 do general-purpose output 28. function is selected using the mfr_gpo_config command. k10 fault1 dio fault input/output 1. open-drain, active-low. see the expanded bump description section for more details. gpo29 do general-purpose output 29. function is selected using the mfr_gpo_config command. j10 fault2 dio fault input/output 2. open-drain, active-low. see the expanded bump description section for more details. gpo30 do general-purpose output 30. function is selected using the mfr_gpo_config command. h9 fault3 dio fault input/output 3. open-drain, active-low. see the expanded bump description for more details. gpo31 do general-purpose output 31. function is selected using the mfr_gpo_config command. g9 psen0 do power-supply enable 0. see the expanded bump description section for more details. gpo0 do general-purpose output 0 f8 psen1 do power-supply enable 1. see the expanded bump description section for more details. gpo1 do general-purpose output 1 g10 psen2 do power-supply enable 2. see the expanded bump description section for more details. gpo2 do general-purpose output 2 f7 psen3 do power-supply enable 3. see the expanded bump description section for more details. gpo3 do general-purpose output 3 f9 psen4 do power-supply enable 4. see the expanded bump description section for more details. gpo4 do general-purpose output 4 e8 psen5 do power-supply enable 5. see the expanded bump description section for more details. gpo5 do general-purpose output 5 f10 psen6 do power-supply enable 6. see the expanded bump description section for more details. gpo6 do general-purpose output 6 e7 psen7 do power-supply enable 7. see the expanded bump description section for more details. gpo7 do general-purpose output 7 h5 psen8 do power-supply enable 8. see the expanded bump description section for more details. gpo8 do general-purpose output 8 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 17 bump description (continued) downloaded from: http:///
bump name type function k7 psen9 do power-supply enable 9. see the expanded bump description section for more details. gpo9 do general-purpose output 9 f6 psen10 do power-supply enable 10. see the expanded bump description section for more details. gpo10 do general-purpose output 10 j6 psen11 do power-supply enable 11. see the expanded bump description section for more details. gpo11 do general-purpose output 11 h6 psen12 do power-supply enable 12. see the expanded bump description section for more details. gpo12 do general-purpose output 12 g6 psen13 do power-supply enable 13. see the expanded bump description section for more details. gpo13 do general-purpose output 13 j7 psen14 do power-supply enable 14. see the expanded bump description section for more details. gpo14 do general-purpose output 14 h7 psen15 do power-supply enable 15. see the expanded bump description section for more details. gpo15 do general-purpose output 15 a9 dac0 ao margining dac output 0. see the expanded bump description section for more details. gpo16 do general-purpose output 16 b8 dac1 ao margining dac output 1. see the expanded bump description section for more details. gpo17 do general-purpose output 17 a8 dac2 ao margining dac output 2. see the expanded bump description section for more details. gpo18 do general-purpose output 18 c7 dac3 ao margining dac output 3. see the expanded bump description section for more details. gpo19 do general-purpose output 19 a6 dac4 ao margining dac output 4. see the expanded bump description section for more details. gpo20 do general-purpose output 20 b6 dac5 ao margining dac output 5. see the expanded bump description section for more details. gpo21 do general-purpose output 21 c6 dac6 ao margining dac output 6. see the expanded bump description section for more details. gpo22 do general-purpose output 22 a5 dac7 ao margining dac output 7. see the expanded bump description section for more details. gpo23 do general-purpose output 23 d6 dac8 ao margining dac output 8. see the expanded bump description section for more details. gpo24 do general-purpose output 24 e4 dac9 ao margining dac output 9. see the expanded bump description section for more details. gpo25 do general-purpose output 25 d5 dac10 ao margining dac output 10. see the expanded bump description section for more details. gpo26 do general-purpose output 26 d4 dac11 ao margining dac output 11. see the expanded bump description section for more details. gpo27 do general-purpose output 27 d3 dac12 ao margining dac output 12. see the expanded bump description section for more details. c3 dac13 ao margining dac output 13. see the expanded bump description section for more details. c4 dac14 ao margining dac output 14. see the expanded bump description section for more details. b5 dac15 ao margining dac output 15. see the expanded bump description section for more details. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 18 bump description (continued) downloaded from: http:///
note: all pins except the power pins and addr and gpo34 are high impedance during device power-up and during device reset. di = digital input, do = digital output, dio = digital input/output, ai = analog input, ao = analog output bump name type function d10 sync dio sequencing synchronization clock. this pin can be conigured using the mfr_mode command to be either an output (master mode) which provides a 20khz clock or an input which accepts a 20khz clock (slave mode) to share the same clock across multiple devices in order to synchronize the time base used for power-supply sequencing. a series 100 resistor is recommended to isolate outputs if two masters share the same bus. leave open circuit if unused. gpo35 do general-purpose output 35. function is selected using the mfr_gpo_config command. f3 vref ao voltage reference output for analog circuitry. bypass to avss with 22nf. do not connect other circuitry to this pin. b9 dvdd power digital supply voltage. bypass to dvss with 0.1f. connect all dvdd and avdd pins together. f5 dvdd power digital supply voltage. bypass to dvss with 0.1f. connect all dvdd and avdd pins together. g8 dvdd power digital supply voltage. bypass to dvss with 0.1f. connect all dvdd and avdd pins together. b10 dvss power digital supply ground reference. connect all dvss and avss pins together. k9 dvss power digital supply ground reference. connect all dvss and avss pins together. g7 dvss power digital supply ground reference. connect all dvss and avss pins together. e6 dvss power digital supply ground reference. connect all dvss and avss pins together. k6 dvss power digital supply ground reference. connect all dvss and avss pins together. g5 reg18 power regulator for digital circuitry. bypass to avss with 1f (500m maximum esr) and 10nf. do not connect other circuitry to this pin. a10 reg18a power supplemental bypass for regulator for digital circuitry. bypass to avss with 0.1f. do not connect other circuitry to this pin. b7 avss power analog supply ground reference. connect all dvss and avss pins together. c5 avss power analog supply ground reference. connect all dvss and avss pins together. g3 avss power analog supply ground reference. connect all dvss and avss pins together. f4 avdd power analog supply voltage. bypass to avss with 0.1f. connect all dvdd and avdd pins together. e3 avdd power analog supply voltage. bypass to avss with 0.1f. connect all dvdd and avdd pins together. a7 avdd power analog supply voltage. bypass to avss with 0.1f. connect all dvdd and avdd pins together. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 19 bump description (continued) downloaded from: http:///
bump expanded description psen the psen open-drain outputs are 5v tolerant and they are programmable with the mfr_psen_config comma nd for either active-high or active-low operation. if not used for power-supply enables, these outputs can be repurposed as general purpose outputs (gpo) using the mfr_psen_config command. if these pins are used to enable power supplies, it is highly recommended that these pins have external pullups or pulldowns to force the supplies into an off state when the device is not active. dac the dac outputs are high-impedance when the margining is disabled. if dac0 to dac11 are not used for margining, these pins can be repurposed as a general purpose outputs (gpo) with the mfr_dac_config command. fault all fault pins operate independently. any global channel can be enabled with the mfr_fault_response command to assert one or more of the fault signals. also each global channel can be enabled to shut down when one or more of the fault signals asserts. these pins are used to provide hardware control for power supplies across multiple devices. these outputs are unconditionally deasserted while rst is asserted or when the device is power cycled. after device reset and upon device power-up, these outputs are pulled low immediately after program recall and held low until monitoring starts. once monitoring starts, the fault signals are released if no enabled faults are present. 1 2 3 4 5 6 7 8 9 10 a rsp0 rsn0 rsp12 rsp13 dac7 dac4 avdd dac2 dac0 reg18a b rsn1 rsp1 rsn12 rsn13 dac15 dac5 avss dac1 dvdd dvss c rsn2 rsp2 dac13 dac14 avss dac6 dac3 mscl msda rst d rsn3 rsp3 dac12 dac11 dac10 dac8 seq sda scl sync e rsp4 rsn4 avdd dac9 gpo33 dvss psen7 psen5 addr gpo34 f rsp5 rsn5 vref avdd dvdd psen10 psen3 psen1 psen4 psen6 g rsp6 rsn6 avss control0 reg18 psen13 dvss dvdd psen0 psen2 h rsp7 rsn7 rsp11 rsn11 psen8 psen12 psen15 control2 fault3 alert j rsp8 rsn8 rsn10 rsn14 rsn15 psen11 psen14 control3 fault0 fault2 k rsp9 rsn9 rsp10 rsp14 rsp15 dvss psen9 control1 dvss fault1 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 20 expanded bump description csbga bump map downloaded from: http:///
pmbus control and monitoring engine pmbus interface dac12Cdac15 dac0Cdac11 gpo16Cgpo27 psen0Cpsen15 gpo0Cgpo15 smbus master msda open drainopen drain open drain open drain open drain mscl min/max and average results adc results sram nv fault log nv configuration sequencing engine sample averaging max34462 temp sensor v ref 2.048v auto sequencer 12-bit 1msps adc mux voltage/current/temperature smbus slave digital power control 1.8v vreg sda scl alert addr rst dvdd reg18/18a dvss pullup sync (gpo35) control3 control2 control1control0 v ref 2.048v avss avdd threshold excursions fault or seq digital comparators undervoltage warning undervoltage fault overvoltage warning overvoltage fault powerCgood on powerCgood off overtemperature warning overtemperature fault gpi logic activeChigh gpi logic activeClow sequencing enable and alarms power-supply enable pin function select alarms power good/gpi margining control 3 3 3 2 5 16 16 rsn0Crsn15 gpin0Cgpin15 rsp0Crsp15 gpip0Cgpip15 16 16 16 16 16 open drain enable and alarms pin function select 12 4 16 16 16 fault0 (gpo28) fault1 (gpo29) fault2 (gpo30) fault3 (gpo31) seq (gpo32) gpo33 gpo34 enable and alarms pin function select 16 16 7 8-bit dac analog power control max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 21 block diagram downloaded from: http:///
detailed description the max34462 is a highly-integrated system monitor with functionality to monitor up to 16 different voltages or currents and also to sequence and close-loop margin up to 16 power supplies. it also supports local and remote thermal sensing. the power-supply manager monitors the power-supply output voltage and current and constantly checks for user- programmable overvoltage, undervoltage, and overcurrent thresholds. it can also margin the power-supply output volt - age up or down by a user-programmable level. the mar - gining is performed in a closed-loop arrangement, whereby the device automatically adjusts a dac output voltage and then measures the resultant output voltage. the power- supply manager can also sequence the supplies in any order at both power-up and power-down. thermal monitoring can be accomplished using up to five temperature sensors including an on-chip temperature sensor and up to four external remote ds75lv digital temperature sensors. communications with the ds75lv temperature sensors is conducted via a dedicated i 2 c/ smbus interface. the max34462 provides alert and multiple fault out - put signals. host communications are conducted through a pmbus-compatible communications port. see table 1 and table 2 for more details on specific device operation. table 3 shows the pmbus command codes. table 1. pmbus page to pin/resource mapping pin name rs/gpi (16 available) psen/gpo (16 available) dac/gpo (16 available (12 gpo)) pmbus page voltage or current monitor general- purpose input (gpi) ball power- supply enable (psen) general- purpose output (gpo) ball dac margin output (dac) general- purpose output (gpo) ball 0 rs0 gpi0 a1/a2 psen0 gpo0 g9 dac0 gpo16 a9 1 rs1 gpi1 b2/b1 psen1 gpo1 f8 dac1 gpo17 b8 2 rs2 gpi2 c2/c1 psen2 gpo2 g10 dac2 gpo18 a8 3 rs3 gpi3 d2/d1 psen3 gpo3 f7 dac3 gpo19 c7 4 rs4 gpi4 e1/e2 psen4 gpo4 f9 dac4 gpo20 a6 5 rs5 gpi5 f1/f2 psen5 gpo5 e8 dac5 gpo21 b6 6 rs6 gpi6 g1/g2 psen6 gpo6 f10 dac6 gpo22 c6 7 rs7 gpi7 h1/h2 psen7 gpo7 e7 dac7 gpo23 a5 8 rs8 gpi8 j1/j2 psen8 gpo8 h5 dac8 gpo24 d6 9 rs9 gpi9 k1/k2 psen9 gpo9 k7 dac9 gpo25 e4 10 rs10 gpi10 k3/j3 psen10 gpo10 f6 dac10 gpo26 d5 11 rs11 gpi11 h3/h4 psen11 gpo11 j6 dac11 gpo27 d4 12 rs12 gpi12 a3/b3 psen12 gpo12 h6 dac12 n/a d3 13 rs13 gpi13 a4/b4 psen13 gpo13 g6 dac13 n/a c3 14 rs14 gpi14 k4/j4 psen14 gpo14 j7 dac14 n/a c4 15 rs15 gpi15 k5/j5 psen15 gpo15 h7 dac15 n/a b5 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 22 downloaded from: http:///
table 2. device channel capabilities and options table 3. pmbus command codes max34462 channel pmbus command page channel capabilities 0 to 15 0 to 15 voltage monitor/sequence/margin/gpo option pins rs/gpi, psen, and dac (where n = 0 to 15) have a one-to-one association for each channel that monitors for voltage (rs) and can be used to sequence (psen) and margin (dac) the power supply. the voltage monitored on this channel can also be conigured to determine a power-good state. if not required for either sequencing or margining, the associated psen and dac outputs (only for dac channels 0 to 11) can be repurposed as gpo outputs that can either indicate a logic combination of power-good (pg) and gpi states or report alarms. current monitor/gpo option if the rs/gpi input is used to monitor current, then the channel is not used to sequence or margin. the associated psen and dac outputs (only for dac channels 0 to 11) can be repurposed as gpo outputs that can either indicate a logic combination of power-good (pg) and gpi states or report alarms. gpi/gpo option if the rs/gpi input is conigured as a general-purpose input (gpi), then it can be used as a term in a logic combination to determine a power-good (pg) state and assert a gpo output or act as a condition to allow a power supply to be enabled. the associated psen and dac outputs (only for dac channels 0 to 11) can be repurposed as gpo outputs that can be indicate power-good (pg) states or report alarms. code command name type page (note 1) # byte flash stored/ locked (note 2) default value (note 2) 0-15 16- 20 21- 28 255 00h page r/w byte r/w r/w r/w r/w 1 n/n 00h 01h operation r/w byte r/w w 1 n/n 00h 02h on_off_config r/w byte r/w r/w r/w r/w 1 y/y 1ah 03h clear_faults send byte w w w w 0 n/n 10h write_protect r/w byte r/w r/w r/w r/w 1 n/y 00h 11h store_default_all send byte w w w w 0 n/y 12h restore_default_all send byte w w w w 0 n/y 19h capability read byte r r r r 1 n/n 20h/30h 20h vout_mode read byte r r r r 1 fixed/n 40h 21h vout_command r/w word r/w 2 y/y 0000h 25h vout_margin_high r/w word r/w 2 y/y 0000h 26h vout_margin_low r/w word r/w 2 y/y 0000h 2ah vout_scale_monitor r/w word r/w 2 y/y 7fffh 38h iout_cal_gain r/w word r/w 2 y/y 0000h 40h vout_ov_fault_limit r/w word r/w 2 y/y 7fffh 42h vout_ov_warn_limit r/w word r/w 2 y/y 7fffh 43h vout_uv_warn_limit r/w word r/w 2 y/y 0000h max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 23 downloaded from: http:///
table 3. pmbus command codes (continued) code command name type page (note 1) # byte flash stored/ locked (note 2) default value (note 2) 0-15 16- 20 21- 28 255 44h vout_uv_fault_limit r/w word r/w 2 y/y 0000h 46h iout_oc_warn_limit r/w word r/w 2 y/y 7fffh 4ah iout_oc_fault_limit r/w word r/w 2 y/y 7fffh 4fh ot_fault_limit r/w word r/w 2 y/y 7fffh 51h ot_warn_limit r/w word r/w 2 y/y 7fffh 5eh power_good_on r/w word r/w 2 y/y 0000h 5fh power_good_off r/w word r/w 2 y/y 0000h 60h ton_delay r/w word r/w 2 y/y 0000h 62h ton_max_fault_limit r/w word r/w 2 y/y ffffh 64h toff_delay r/w word r/w 2 y/y 0000h 79h status_word read word r r r r 2 n/n 0000h 7ah status_vout read byte r 1 n/n 00h 7bh status_iout read byte r 1 n/n 00h 7dh status_temperature read byte r 1 n/n 00h 7eh status_cml read byte r r r r 1 n/n 00h 80h status_mfr_specific read byte r r 1 n/n 00h 8bh read_vout read word r 2 n/n 0000h 8ch read_iout read word r 2 n/n 0000h 8dh read_temperature_1 read word r 2 n/n 0000h 98h pmbus_revision read byte r r r r 1 fixed/n 11h 99h mfr_id read byte r r r r 1 fixed/n 4dh 9ah mfr_model read byte r r r r 1 fixed/n 5ah 9bh mfr_revision read word r r r r 2 fixed/n (note 3) 9ch mfr_location block r/w r/w r/w r/w r/w 8 y/y (note 4) 9dh mfr_date block r/w r/w r/w r/w r/w 8 y/y (note 4) 9eh mfr_serial block r/w r/w r/w r/w r/w 8 y/y (note 4) d1h mfr_mode block r/w r/w r/w r/w r/w 2 y/y 0020h d2h mfr_psen_config block r/w r/w 4 y/y (note 5) d4h mfr_vout_peak r/w word r/w 2 n/y 0000h d5h mfr_iout_peak r/w word r/w 2 n/y 0000h d6h mfr_temperature_peak r/w word r/w 2 n/y 8000h d7h mfr_vout_min r/w word r/w 2 n/y 7fffh d8h mfr_nv_log_config r/w word r/w r/w r/w r/w 2 y/y 0000h d9h mfr_fault_response block r/w r/w 4 y/y (note 5) dah mfr_fault_retry r/w word r/w r/w r/w r/w 2 y/y 0000h dch mfr_nv_fault_log block read r r r r 255 y/y (note 6) ddh mfr_time_count block r/w r/w r/w r/w r/w 4 n/y (note 5) dfh mfr_margin_config r/w word r/w 2 y/y 0000h e2h mfr_iout_avg r/w word r 2 n/y 0000h e4h mfr_channel_config r/w word r/w 2 y/y 0000h max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 24 downloaded from: http:///
note 1: common commands are shaded. access via any page results in the same device response. note 2: in the flash stored/locked column, the left n indicates that this parameter is not stored in flash memory when the store_default_all or mfr_store_all command is executed and the value shown in the default value column is automatically loaded upon power-on reset or when the rst pin is asserted. the left y in the flash stored/locked col - umn indicates that the currently loaded value in this parameter is stored in flash memory when the s tore_default_all or mfr_store_all command is executed and is automatically loaded upon power-on reset or when the rst pin is asserted and the value shown in the default value column is the value when shipped from the factory. fixed in the flash stored column means this value is fixed at the factory and cannot be changed. the value shown in the default value column is automatically loaded upon power-on reset or when the rst pin is asserted. the right side y/n indicates that when the device is locked, only the commands listed with n can be accessed. all other command s are ignored if writ - ten and return ffh if read. only the page, clear_faults, operation, and mfr_serial commands can be w ritten to. the device unlocks if the upper 4 bytes of mfr_serial match the data written to the device. note 3: the factory-set value is dependent on the device hardware and firmware revision. note 4: the factory-set default value for this 8-byte block is 3130313031303130h. note 5: the factory-set default value for this 4-byte block is 00000000h. note 6: the factory-set default value for the complete block of the mfr_nv_fault_log is ffh. note 7: mfr_dac_config is only available for pages 0 to 11. table 3. pmbus command codes (continued) code command name type page (note 1) # byte flash stored/ locked (note 2) default value (note 2) 0-15 16- 20 21- 28 255 e6h mfr_ton_seq_max r/w word r/w 2 y/y 0000h e8h mfr_seq_config block r/w r/w 4 y/y (note 5) e9h mfr_dac_config (note 7) block r/w r/w 4 y/y (note 5) eeh mfr_store_all write byte w w w w 1 n/y efh mfr_restore_all write byte w w w w 1 n/y f0h mfr_temp_sensor_config r/w word r/w 2 y/y 0000h f8h mfr_gpo_config block r/w r/w 4 y/y (note 5) fch mfr_store_single r/w word r/w r/w r/w r/w 2 n/y 0000h feh mfr_crc r/w word r/w r/w r/w r/w 2 n/y ffffh max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 25 downloaded from: http:///
note: the device also responds to a slave address of 34h (this is the factory programming address) and the devices should not share the same i 2 c bus with other devices that use this slave address. pmbus/smbus address select on device power-up, the device samples the addr pin to determine the pmbus/smbus serial-port address. the combination of the components shown in figure 1 deter - mines the serial-port address (also see table 4 ). smbus/pmbus operation the device implements the pmbus command structure using the smbus format. the structure of the data flow between the host and the slave is shown below for sev - eral different types of transactions. all transactions begin with a host sending a command code, which is immedi - ately preceded with a 7-bit slave address (r/ w = 0). data is sent msb first. figure 1. pmbus/smbus address select table 4. pmbus/smbus serial port address r1 r2 r3 r4 c2 7-bit slave address 220k 1110 100 (e8h) 220k 1110 101 (eah) 220k 100nf 0010 010 (24h) 22k 100nf 0010 011 (26h) 0k 1001 100 (98h) 220k 1001 101 (9ah) 0k 1011 000 (b0h) 220k 1011 001 (b2h) 0k 1001 110 (9ch) msdamscl max34462 addr r1r2 c2 r3 r4 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 26 downloaded from: http:///
smbus/pmbus operation examples read word format 1 7 1 1 8 1 1 7 1 1 8 1 8 1 1 s slave address w a command code a sr slave address r a data byte low a data byte high na p read byte format 1 7 1 1 8 1 1 7 1 1 8 1 1 s slave address w a command code a sr slave address r a data byte na p write word format 1 7 1 1 8 1 8 1 8 1 1 s slave address w a command code a data byte low a data byte high a p write byte format 1 7 1 1 8 1 8 1 1 s slave address w a command code a data byte a p send byte format 1 7 1 1 8 1 1 s slave address w a command code a p key: s = start sr = repeated start p = stop w = write bit (0) r = read bit (1) a = acknowledge (0) na = not acknowledge (1) shaded block = slave transaction max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 27 downloaded from: http:///
group command the max34462 supports the group command. with the group command, a host can write different data to multiple devices on the same serial bus with one long continuous data stream. all the devices addressed during this transaction waits for the host to issue a stop before beginning to respond to the command. group command write format addressing the device responds to receiving its fixed slave address by asserting an acknowledge (ack) on the bus. the device does not respond to a general call address; it only responds when it receives its fixed slave address or the alert response address. see the alert and alert response address (ara) section for more details. alert and alert response address (ara) if the alert output is enabled (alert bit = 1 in mfr_ mode), when a fault occurs, the device asserts the alert signal and then waits for the host to send the alert response address (ara), as shown below. alert response address (ara) byte format 1 7 1 1 8 1 1 s ara 0001100 r a device slave address with lsb = 0 na p when the ara is received and the device is asserting alert , the device acks it and then attempts to place its fixed slave address on the bus by arbitrating the bus, since another device may also try to respond to the ara. the rules of arbitration state that the lowest address device wins. if the device wins the arbitration, it deasserts alert . if the device loses arbitration, it keeps alert asserted and waits for the host to once again send the ara. host sends or reads too few bits if for any reason, the host does not complete writing a full byte or reading a full byte from the device before a start or stop is received, the device does the following: 1) ignores the command. 2) sets the cml bit in status_word. 3) sets the data_fault bit in status_cml. 4) notifies the host through alert assertion (if enabled). slave address, command byte, and data word for device 1 1 7 1 1 8 1 8 1 8 1 s slave address w a command code a data byte low a data byte high a u u u slave address, command byte, and data byte for device 2 1 7 1 1 8 1 8 1 sr slave address w a command code a data byte a u u u slave address and send byte for device 3 1 7 1 1 8 1 sr slave address w a command code a u u u u u u slave address, command byte, and data word for device n 1 7 1 1 8 1 8 1 8 1 1 sr slave address w a command code a data byte low a data byte high a p key: s = start sr = repeated start p = stop w = write bit (0) r = read bit (1) a = acknowledge (0) na = not acknowledge (1) shaded block = slave transaction max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 28 downloaded from: http:///
host sends or reads too few bytes for each supported command, the device expects a fixed number of bytes to be written or read from the device. if, for any reason, less than the expected number of bytes is written to or read from the device, the device completely ignores the command and takes no action. host sends too many bytes or bits for each supported command, the device expects a fixed number of bytes to be written to the device. if, for any reason, more than the expected number of bytes or bits is written to the device, the device does the following: 1) ignores the command. 2) sets the cml bit in status_word. 3) sets the data_fault bit in status_cml. 4) notifies the host through alert assertion (if enabled). host reads too many bytes or bits for each supported command, the device expects a fixed number of bytes to be read from the device. if, for any reason, more than the expected number of bytes or bits is read from the device, the device does the following: 1) sends all ones (ffh) as long as the host keeps acknowledging. 2) sets the cml bit in status_word. 3) sets the data_fault bit in status_cml. 4) notifies the host through alert assertion (if enabled). host sends improperly set read bit in the slave address byte if the device receives the r/ w bit in the slave address set to a one immediately preceding the command code, the device acts as follows. note this does not apply to ara. 1) acks the address byte. 2) sends all ones (ffh) as long as the host keeps acknowledging. 3) sets the cml bit in status_word. 4) sets the data_fault bit in status_cml. 5) notifies the host through alert assertion (if enabled). unsupported command code received/host writes to a read-only command if the host sends the device a command code that it does not support, or if the host sends a command code that is not supported by the current page setting, the device does the following: 1) ignores the command. 2) sets the cml bit in status_word. 3) sets the comm_fault bit in status_cml. 4) notifies the host through alert assertion (if enabled). invalid data received the device checks the page, operation, and write_ protect command codes for valid data. if the host writes a data value that is invalid, the device does the following: 1) ignores the command. 2) sets the cml bit in status_word. 3) sets the data_fault bit in status_cml. 4) notifies the host through alert assertion (if enabled). host reads from a write-only command when a read request is issued to a write-only command (clear_faults, store_default_all, restore_ default_all, mfr_store_all, mfr_restore_ all, operation with page = 255), the device does the following: 1) acks the address byte. 2) ignores the command. 3) sends all ones (ffh) as long as the host keeps acknowledging. 4) sets the cml bit in status_word. 5) sets the data_fault bit in status_cml. 6) notifies the host through alert assertion (if enabled). smbus timeout if, during an active smbus communication sequence, the scl signal is held low for greater than the timeout duration (nominally 27ms), the device terminates the sequence and resets the serial bus. it takes no other action. no status bits are set. pmbus operation from a software perspective, the device appears as a pmbus device capable of executing a subset of pmbus commands. a pmbus 1.1-compliant device uses the smbus version 1.1 for transport protocol and responds to the smbus slave address. in this data sheet, the term smbus is used to refer to the electrical characteristics of the pmbus communication using the smbus physical layer. the term pmbus is used to refer to the pmbus command protocol. the device employs a number of standard smbus protocols (e.g., write word, read word, write byte, read byte, send byte, etc.) to program output voltage and warning/faults thresholds, read monitored data, and provide access to all manufacturer-specific commands. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 29 downloaded from: http:///
the device supports the group command. the group command is used to send commands to more than one pmbus device. it is not required that all the devices receive the same command. however, no more than one command can be sent to any one device in one group command packet. the group command must not be used with commands that require receiving devices to respond with data, such as the status_word command. when the device receives a command through this protocol, it immediately begins execution of the received command after detecting the stop condition. the device supports the page command and uses it to select which individual channel to access. when a data word is transmitted, the lower order byte is sent first and the higher order byte is sent last. within any byte, the most significant bit (msb) is sent first and the least signifi - cant bit (lsb) is sent last. pmbus protocol support the device supports a subset of the commands defined in the pmbus power system management protocol specification part ii - command language revision 1.1. for detailed specifications and the complete list of pmbus commands, refer to part ii of the pmbus specification available at www.pmbus.org. the supported pmbus commands and the corresponding max34462 behav - ior are described in this document. all data values are represented in direct format, unless otherwise stated. whenever the pmbus specification refers to the pmbus device, it is referring to the max34462 operating in con - junction with a power supply. while the command may call for turning on or off the pmbus device, the max34462 always remains on to continue communicating with the pmbus master and the max34462 transfers the com - mand to the power supply accordingly. table 5. pmbus command code coefficients parameter commands units resolution maximum m b r voltage vout_commandvout_margin_high vout_margin_low vout_ov_fault_limit vout_ov_warn_limit vout_uv_warn_limit vout_uv_fault_limit power_good_on power_good_off read_vout mfr_vout_peak mfr_vout_min mv 1 32,767 1 0 0 voltage scaling vout_scale_monitor 1/32,767 1 32,767 0 0 current iout_oc_fault_limit iout_oc_warn_limit read_iout mfr_iout_peak mfr_iout_avg a 0.01 327.67 1 0 2 current scaling iout_cal_gain m? 0.1 3276.7 1 0 1 temperature ot_fault_limit ot_warn_limit read_temperature_1 mfr_temperature_peak c 0.01 327.67 1 0 2 timing ton_delay ton_max_fault_limit toff_delay mfr_fault_retry mfr_ton_seq_max ms 0.2 6553.4 5 0 0 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 30 downloaded from: http:///
data format voltage data for commanding or reading the output voltage or related parameters (such as the overvoltage threshold) are presented in direct format. direct format data is a 2-byte, twos complement binary value. direct format data may be used with any command that sends or reads a parametric value. the direct format uses an equation and defined coefficients to calculate the desired values. the coefficients used by the device can be found in table 5 . interpreting received direct format values the host system uses the following equation to convert the value received from the pmbus device, in this case the max34462, into a reading of volts, degrees celsius, or other units as appropriate: x = (1/m) x (y x 10 -r - b) where: x = calculated, real world value in the appropriate units (v, c, etc.) m = slope coefficient y = 2-byte, twos complement integer received from the pmbus device b = offset r = exponent sending a direct format value to send a value, the host must use the equation below to solve for y: y = (mx + b) x 10 r where: y = 2-byte, twos complement integer to be sent to the unit m = slope coefficient x = real world value, in units such as volts, to be con - verted for transmission b = offset r = exponent the following example demonstrates how the host can send and retrieve values from the device. table 6 lists the coefficients used in the following parameters. if a host wants to set the device to change the power- supply output voltage to 3.465v (or 3465mv), the corre - sponding vout_margin_high value is: y = (1 x 3465 + 0) x 10 0 = 3465 (decimal) = 0d89h (hex) conversely, if the host received a value of 0d89h on a read_vout command, this is equivalent to: x = (1/1) x (0d89h x 10 -(-0) C 0) = 3465mv = 3.465v power supplies and power converters generally have no way of knowing how their outputs are connected to ground. within the power supply, all output voltages are most commonly treated as positive. accordingly, all output voltages and output voltage-related parameters of pmbus devices are commanded and reported as positive values. it is up to the system to know that a particular output is negative if that is of interest to the system. all output voltage-related commands use 2 data bytes. fault management and reporting for reporting faults/warnings to the host on a real-time basis, the device asserts the open-drain alert (if enabled in mfr_mode) pin and sets the appropriate bit in the various status registers. on recognition of the alert assertion, the host or system manager is expect - ed to poll the i 2 c bus to determine the device asserting alert . the host sends the smbus alert response address (0001 100). the device acks the smbus ara, transmit its slave address, and deasserts alert . the system controller then communicates with pmbus com - mands to retrieve the fault/warning status information from the device. see the individual command sections for more details. faults and warnings that are latched in the status regis - ters are cleared when any one of the following conditions occurs: a clear_faults command is received. rst pin is toggled or a soft reset is issued. bias power to the device is removed and then reapplied. one or more latched off power supplies are only restarted when one of the following occurs: operation commands are received that turn off and on the power supplies or the control0/1/2/3 pin is toggled to turn off and then turn on the power supplies. rst pin is toggled or a soft reset is issued. bias power to the device is removed and then reapplied. table 6. coefficients for direct format value command code command name m b r 25h vout_margin_high 1 0 0 8bh read_vout 1 0 0 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 31 downloaded from: http:///
note: device response to faults is determined by the configuration of mfr_fault_response. the device responds to fault conditions according to the configuration of the mfr_fault_response com - mand. this command determines how the device should respond to each particular fault and whether it should assert one of more of the fault pins when a fault occurs. the mfr_fault_response command also deter - mines whether a channel should power-up if a fault is present. with the response bits in mfr_fault_ response, each channel can be independently config - ured to either respond (or not respond) to each possible fault. before any power-supply channel is enabled or the fault outputs are deasserted, the device checks for overvoltage, overcurrent, and temperature faults (but not for undervoltage) if the channel is configured for a fault response to either latchoff (response[1:0] = 01) or retry (response[1:0] = 10) in the mfr_fault_repsonse command. only after the faults clear is the channel allowed to turn on. see table 7 for fault-monitoring states. password protection the device can be password protected by using the lock bit in the mfr_mode command. once the device is locked, only certain pmbus commands can be accessed with the serial port. see table 3 for a complete list of commands. commands that have password protection return all ones (ffh) with the proper number of data bytes when read. when the device is locked, only the page, operation, clear_faults, and mfr_serial com - mands can be written; all other written commands are ignored. when mfr_serial is written and the upper 4 bytes match the internally flash-stored value, the device unlocks and remains unlocked until the lock bit in mfr_ mode is activated once again. the lock status bit in status_mfr_specific is always available to indicate whether the device is locked or unlocked. power-supply sequencing sequencing control for each of the 16 power-supply chan - nels on the device is configured using the mfr_seq_ config and on_off_config commands. see the descriptions of these commands for details on the exact device configuration required. power supplies can be powered up and down in any order even across multiple devices. see the command descriptions and figure 2 for specifics on sequencing control. table 7. fault-monitoring states fault required device configuration for active monitoring when monitored overvoltage ? voltage monitoring enabled (select[5:0] = 10h or 20h in mfr_channel_config) continuous monitoring. undervoltage ? voltage monitoring enabled (select[5:0] = 10h or 20h in mfr_channel_config) stop monitoring while the power supply is off; start monitoring when voltage exceeds the power_good_on level. overcurrent ? current monitoring enabled (select[5:0] = 22h in mfr_channel_config) continuous monitoring. power-up time ? sequencing enabled (select[5:0] = 10h in mfr_channel_config) monitored only during power-on sequence. overtemperature ? temperature sensor enabled (enable = 1 in mfr_temp_sensor_config) continuous monitoring. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 32 downloaded from: http:///
quad-loop sequencing the device contains four independent sequencing groups: sequence0, sequence1, sequence2, and sequence3. all groups do not need to be used, but every channel is assigned to one of the groups with the seq_select bits in the mfr_seq_config com - mand. the four sequencing groups operate independent - ly. sequence0 is always associated with control0 and sequence1 is always associated with control1, and so on. the four sequencing groups can also be inde - pendently controlled with the operation command. with the on_off_config command, the device is configured to respond to control0/1/2/3 pins or the operation command (or both). when the operation command is sent to the device when the page is set to 255, all four sequence groups are controlled as shown in table 8 . table 8. operation command sequence control options figure 2. sequence control logic group operation command (page = 255) on soft-off immediate off sequence0 80h or 81h 40h or 41h 00h or 01h sequence1 80h or 82h 40h or 42h 00h or 02h sequence2 80h or 83h 40h or 43h 00h or 03h sequence3 80h or 84h 40h or 44h 00h or 04h mfr_ton_seq_max seq match select select on_off_config mfr_seq_config bits 16C31 bits 0C1 bits 8 C11 bits 4C5 bit 14 bit 27 bit 26 bit 25 bit 24 or and and or jk on off stop start psen0Cpsen15 powerCsupply enables sequence0 seq pg0/gpi0 C pg15/gpi15 fault1 fault2 fault3 sequence3 sequence2 sequence1 16 power-on operation command control0/1/2/3 16 global/ local select or and and and global local mfr_fault_response local0Clocal15 note: signals listed in italics are internal signals that connect to other device functions. shaded blocks are pmbus commands. fault0 and max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 33 downloaded from: http:///
power-on sequencing the activation of all power-supply channels (even across multiple devices) is initiated from a common start signal that can be either the control pins or the operation command. each power-supply channel on the device can be sequenced on by one of the following methods. power applied to the device. the control0 pin goes active. the control1 pin goes active. the control2 pin goes active. the control3 pin goes active. the operation command is received. the logic combination of power-goods and gpi is valid. the seq pin signal is matched. each enabled psen output goes active (can be active high or low as defined in mfr_psen_config) after the associated delay time programmed in ton_delay. the power supplies can be sequenced on in any order. each channel can be sequenced on with either time-based or event-based conditions. the output voltage of each power supply is monitored to make sure that the supply crosses the power-good on level (as configured in the power_good_on command) within a programmable time limit as configured in the ton_max_fault_limit command. this power-up time limit can be disabled by configuring ton_max_fault_limit to 0000h. for channels using event-based sequencing, the mfr_ton_ seq_max command determines the maximum time limit for the sequence on event to occur. like the ton_max_ fault_limit, this limit can be disabled by configuring mfr_ton_seq_max to 0000h. there is one to one correspondence between rs inputs and psen outputs. for example, rs6 monitors the power supply controlled by psen6. all power-on sequencing is gated by detected faults. before any power-supply channel is enabled (or fault output is deasserted), the device checks for overvoltage, overcurrent, and temperature faults that are enabled (but not for undervoltage since the supply is off). power-off sequencing the order in which the supplies are disabled is deter - mined with the toff_delay configuration. alternatively, all the power supplies can be switched off immediately as configured in the on_off_config command or with the operation command. as configured with the on_off_config command, either the control0/1/2/3 pins or the operation command are the master off switch. when either the control pin goes inactive or the operation off command is received (or one the enabled fault pins is asserted), the power supplies are sequenced off. neither the power-good (pg) and gpi logic combinations nor the seq pin can be used to turn off power supplies. sequencing example for example, figure 3 details a simple sequencing scheme consisting of four power supplies using a mixture of time-based and event-based sequencing. channels 0 and 2 use time-based sequencing and channels 1 and 5 use event-based sequencing. when either the control0/1/2/3 pin goes active or the operation command is received (as defined by the on_off_ config command), psen0 is asserted after the delay time configured in ton_delay. rs0 is monitored to make sure that the psen0 supply crosses the power- good on level (as configured in power_good_on) within a programmable time limit (as configured in ton_max_fault_limit). psen2 operates in a similar fashion as psen0 but with a different ton_delay and a different ton_max_fault_limit. since the power-up of channels 0 and 2 are based solely on their ton_delay values, these channels are time-based. when rs2 crosses its power-good on level, psen5 is asserted after its configured ton_delay and similarly psen1 will assert when rs5 crosses its power-good on level. since the power-up of channels 5 and 1 are based on the power-good states of other channels, these chan - nels are event-based. the mfr_ton_seq_max com - mand can be used to insure these events occur and the power-up sequence does not hang waiting for an event max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 34 downloaded from: http:///
to transpire. when rs1 crosses its power-good on level, it has been configured to generate a seq pin signal to communicate to another device to turn on one or more of its power supplies. multiple device connections multiple max34462 devices can be connected together to increase the system channel count. figure 4 details the recommended connection scheme. all the paralleled devices share the same control, fault , seq , and smbus signals. all the devices use a common signal (either the control0 to control3 pins or the operation command) to enable and disable all the power supplies. any of the monitored power supplies can be configured with the mfr_fault_ response command to activate one or more of the fault signals and shut down all the other supplies enabled to respond to one or more of the fault signals. the use of multiple faults signals allows more flexibility in controlling which power supplies need to shut down during a fault. user note: all devices must be configured with the same on_off_config configuration. all devices must be powered up and reset at the same time. figure 3. sequencing example power_good_on ton_max_fault_limit ton_delay power_good_on ton_max_fault_limit ton_delay power_good_on ton_max_fault_limit ton_delay power_good_on ton_max_fault_limit toff_delay toff_delay toff_delay toff_delay notes 1 and 2 ton_delay power-down power-up control0/1/2/3 pin or operation command psen0 rs0rs2 rs5 rs1 seq psen2psen5 psen1 notes: 1. alternate power-down sequencing operation is to shut off all supplies immediately. 2. the fault pin being asserted low can also cause a power-down sequence to occur. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 35 downloaded from: http:///
figure 4. multiple max34462 hardware connections scl /sda (unique address) control0 max34462 control1 hardware control pmbus control fault0 fault1 fault2 seq (optional) sync (master) fault3 control2control3 scl /sda (unique address) control0 max34462 control1 fault0 fault1 fault2 seq (optional) sync (slave) fault3 control2control3 scl /sda (unique address) control0 max34462 control1 fault0 fault1 fault2 seq (optional) sync (slave) fault3 control2control3 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 36 downloaded from: http:///
seq pin operation the seq pin is an optional signal. when this function is enabled, it allows multiple devices to coordinate event- based sequencing. with the mfr_channel_config command, any channel can be configured to generate one of 15 signatures. when the channel crosses its pow - er-good on level, it generates the needed seq signature if so enabled. with the mfr_seq_config command, any of the sequencing channels (pages 0 to 15) can be configured to wait for a match on the seq pin before asserting the psen output. to ensure that a valid seq signal is received when it should be, the maximum allow - able time is configured into the mfr_ton_seq_max command. user note: only one channel should be configured with any one particular seq signature. if two chan - nels had the same signature, they might reach their power-good on levels at different times and corrupt the seq signal. allow more than 15ms between con - secutive seq signatures. sync pin operation in a multiple device application, one max34462 is config - ured as the sync master and it provides a 20khz clock to the rest of the devices that accept the 20khz clock and slaves their timing to this clock to allow all the devices to use the same clock source for power-supply sequencing. a small series resistor (100) is recommended to pre - vent output shorts should two masters become active at the same time. this should not occur with proper device configuration. the sync master or slave selection is configured with the sync bit in mfr_mode. if the sync pin is config - ured as a slave, then once a second, the device checks whether the sync pin is toggling. if it is not toggling, then the device switches to an internal time base and sets the sync bit in status_mfr_specific (page = 255). once a missing signal is detected, the device adds a weak pullup to the sync input and continues to check once a second for the presence of the sync signal. if a sync signal is detected, the device switches to sync signal and allows the sync status bit to be cleared. system watchdog timer the device uses an internal watchdog timer. this timer is internally reset every 5ms. in the event that the device is locked up and this watchdog reset does not occur after 210ms, the device automatically resets. after the reset occurs, the device reloads all configuration values that were stored to flash and begins normal operation. after the reset, the device also does the following: 1) sets the mfr bit in status_word. 2) sets the watchdog_int bit in status_mfr_ specific (for page 255). 3) notifies the host through alert assertion (if enabled in mfr_mode). crc memory check upon reset, the device runs an internal algorithm to check the integrity of the key internal nonvolatile memory. if the crc check fails, the device does not power up and remains in a null state with all pins high impedance, but does assert the fault0 output. pmbus commands a summary of the pmbus commands supported by the device is described in the following sections. page (00h) the device can monitor up to 16 voltages or currents and it can also sequence and margin up to 16 power supplies. the device can monitor up to five temperature sensors, one internal local temperature sensor plus four external remote temperature sensors (ds75lv). all the monitoring and control is accomplished using one pmbus (i 2 c) address. send the page command with data 0 to 28 (decimal) to select which power supply or temperature sensor or gpo function is affected by all the following pmbus commands. not all commands are sup - ported within each page. if an unsupported command is received, the cml status bit is set. some commands are common, which means that any selected page has the same affect on and the same response from the device. see table 9 for page commands. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 37 downloaded from: http:///
note 1: pages 0 to 15 can also be used to configure gpi and gpo operation. note 2: pages 64 to 92 can be used to write to temporary ram. see the device configuration data management section for details. note 3: set the page to 255 when it is desired that the following pmbus commands should apply to all pages at the same time. there are only a few commands (operation, clear_faults) where this function has a real application. table 9. page (00h) commands page associated control notes 0 power supply monitored by rs0 and controlled by psen0 and margined with dac0 1 1 power supply monitored by rs1 and controlled by psen1 and margined with dac1 1 2 power supply monitored by rs2 and controlled by psen2 and margined with dac2 1 3 power supply monitored by rs3 and controlled by psen3 and margined with dac3 1 4 power supply monitored by rs4 and controlled by psen4 and margined with dac4 1 5 power supply monitored by rs5 and controlled by psen5 and margined with dac5 1 6 power supply monitored by rs6 and controlled by psen6 and margined with dac6 1 7 power supply monitored by rs7 and controlled by psen7 and margined with dac7 1 8 power supply monitored by rs8 and controlled by psen8 and margined with dac8 1 9 power supply monitored by rs9 and controlled by psen9 and margined with dac9 1 10 power supply monitored by rs10 and controlled by psen10 and margined with dac10 1 11 power supply monitored by rs11 and controlled by psen11 and margined with dac11 1 12 power supply monitored by rs12 and controlled by psen12 and margined with dac12 1 13 power supply monitored by rs13 and controlled by psen13 and margined with dac13 1 14 power supply monitored by rs14 and controlled by psen14 and margined with dac14 1 15 power supply monitored by rs15 and controlled by psen15 and margined with dac15 1 16 internal temperature sensor 17 external ds75lv temperature sensor with i 2 c address 90h 18 external ds75lv temperature sensor with i 2 c address 92h 19 external ds75lv temperature sensor with i 2 c address 94h 20 external ds75lv temperature sensor with i 2 c address 96h 21 gpo28 (alternate function is fault0) 22 gpo29 (alternate function is fault1) 23 gpo30 (alternate function is fault2 ) 24 gpo31 (alternate function is fault3 ) 25 gpo32 (alternate function is seq ) 26 gpo33 27 gpo34 28 gpo35 (alternate function is sync) 29C254 reserved 2 255 applies to all pages 3 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 38 downloaded from: http:///
note: all enabled channels must exceed power_good_on for margining to begin. operation (01h) the operation command is used to turn the power supply on and off in conjunction with the control0/1/2/3 input pins. the operation command is also used to cause the power supply to set the output voltage to the upper or lower margin voltages. the power supply stays in the commanded operating mode until a subsequent operation command or a change in the state of the control0/1/2/3 pins (if enabled) instructs the power supply to change to another state. the valid operation command byte values are shown in table 10 . the operation command controls how the device responds when commanded to change the output. when the com - mand byte is 00h, the device immediately turns the power supply off and ignores any programmed turn-off delay. when the command byte is set to 40/41/42/43/44h, the device powers down according to the programmed turn- off delay. in table 10 , table 11 , and table 12 , act on any fault means that if any warning or fault on the selected power supply is detected when the output is margined, the device treats this as a warning or fault and responds as programmed. ignore all faults means that all warnings and faults on the selected power supply are ignored. any com - mand value not shown in the tables is an invalid command. if the device receives a data byte that is not listed in the tables, then it treats this as invalid data, declares a data fault (set cml bit and assert alert ), and responds as described in the fault management and reporting section. in most instances, for power-on and off control, the operation command should be sent when the page is set to 255. if the page is set to 0 to15, the operation command only applies to the power supply on that page, and the power supply is turned on and off using the asso- ciated ton_delay and toff_delay settings without any regard to the other supplies. for individual channel margining control, the operation command can be used with the page set to 0 to 15. when page is set to 255, the operation margining commands affect all channels. the operation command for the device contains a few special values that are not part of the pmbus standard to allow the device to offer independent control. see the shaded values in table 11 . table 10. operation (01h) command byte with page = 0 to 15 (when bit 3 of on_off_config = 1) command byte power supply on/off margin state 00h immediate off (no sequencing) 40h soft-off (with sequencing) 80h on margin off 94h on margin low (ignore all faults) 98h on margin low (act on any fault) a4h on margin high (ignore all faults) a8h on margin high (act on any fault) max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 39 downloaded from: http:///
note 1: special device operation commands are shaded. note 2: when the operation command is read, the device always responds with the standard command. note 3: all enabled channels must exceed power_good_on for margining to begin. note 1: the device only takes action if the supply is enabled. note 2: all enabled channels must exceed power_good_on for margining to begin. note 3: if page is set to 255, sequence0 to sequence3 are affected. table 11. operation (01h) command byte with page = 255 (when bit 3 of on_off_config = 1) table 12. operation (01h) command byte (when bit 3 of on_off_config = 0) command byte power supply on/off sequence affected margin state 00h immediate off (no sequencing) sequence0 to sequence3 01h sequence0 only 02h sequence1 only 03h sequence2 only 04h sequence3 only 40h soft-off (with sequencing) sequence0 to sequence3 41h sequence0 only 42h sequence1 only 43h sequence2 only 44h sequence3 only 80h on sequence0 to sequence3 margin off 81h sequence0 only 82h sequence1 only 83h sequence2 only 84h sequence3 only 94h on sequence0 to sequence3 margin low (ignore all faults) 98h on margin low (act on any fault) a4h on margin high (ignore all faults) a8h on margin high (act on any fault) command byte power supply on/off margin state 00h command has no effect 40h80h margin off 94h margin low (ignore all faults) 98h margin low (act on any fault) a4h margin high (ignore all faults) a8h margin high (act on any fault) max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 40 downloaded from: http:///
note: unless bit 5 is set, if both bits 2 and 3 are set, both the control pins and the operation command are required to turn the supplies on and either can turn the supplies off. on_off_config (02h) the on_off_config command configures the com - bination of control inputs and pmbus operation commands needed to turn the power supply on and off. this indicates how the power supply is commanded when power is applied. the on_off_config message con - tent is described in table 13 . the host should not modify on_off_config while the power supplies are active. the configuration of the on_off_config command applies to all the control pins. all the control pins must have the same polarity. if not all control pins are used, the unused control pins can be either con - nected low or connected to other active control pins. the mfr_seq_config command configures whether a control pin has any direct control or not and the state of unused control pins is ignored. see figure 5 . table 13. on_off_config (02h) command byte figure 5. on_off_config logical control bit number purpose bit value meaning 7:6 reserved n/a always returns 000. 5 operation command & control0/1/2/3 pins and/ or select 0 operation command is anded with control0/1/2/3 pins if both are enabled. 1 operation command is ored with control0/1/2/3 pins if both are enabled. 4 turn on supplies when bias is present or use the control0/1/2/3 pins / operation command 0 turn on the supplies (with sequencing if so conigured) as soon as bias is supplied to the device regardless of the control0/1/2/3 pins. 1 use control0/1/2/3 pins (if enabled) and/or operation command (if enabled). see note below. 3 operation command enable 0 on/off portion of the operation command disabled. 1 operation command enabled. 2 control0/1/2/3pin enable 0 control0 to control3 pins disabled. 1 control0 to control3 pins enabled. 1 control0/1/2/3pin polarity 0 active low (drive low to turn on the power supplies). 1 active high (drive high to turn on the power supplies). 0 control0/1/2/3 pin turn off action 0 use the programmed turn off delay (soft off). 1 turn off the power supplies immediately. select sequence0/1/2/3 select or xor operation command device power-on control0/1/2/3 pin and 0 01 1 nand and and bit 1 bit 3 bit 2 bit 5 bit 4 on_off_config note: signals listed in italics are internal signals that connect to other device functions. shaded blocks are pmbus commands. or max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 41 downloaded from: http:///
note: no fault or error is generated if the host attempts to write to a protected area. clear_faults (03h) the clear_faults command is used to clear any latched fault or warning bits in the status registers that have been set and it also unconditionally deasserts the alert output. this command clears all bits simultane - ously. the clear_faults command does not cause a power supply that has latched off for a fault condition to restart. the state of psen outputs under fault conditions is not affected by this command and will change only if commanded through the operation command or control0/1/2/3 pins. if a fault is still present after the clear_faults command is executed, the fault status bit is immediately set again but alert is not reasserted. alert will only be asserted again when a new fault or warning is detected that occurs after the clear_faults command is executed. this command is write-only. there is no data byte for this command. write_protect (10h) the write_protect command is used to provide protection against accidental changes to the device oper - ating memory. all supported commands may have their parameters read, regardless of the write_protect settings. the write_protect message content is described in table 14 . device coniguration data management the device stores configuration data in both nonvolatile flash memory and volatile ram. the pmbus engine man - ages the device configuration data. see figure 6 . the flash memory has three separate arrays for configu - ration parameters whereas the ram only has two arrays. when a pmbus command is written to the device, it is always written to the ram. if the page has no offset from the page number as listed in table 9 , then the com - mand is written to ram operating. if the page has an offset of 64 decimal then the command is written to ram temporary. only flash stored commands should be written with the offset. commands that are not stored in flash by the device (like operation) are ignored. see table 3 for a list of commands that are flash stored. when the device is shipped from the factory, the main and backup flash memory arrays are identical and they are configured as shown in table 3 . the single array is empty. there is a set of five pmbus commands that can be used to transfer data between the flash and ram arrays. these commands are described in table 15 . table 14. write_protect (10h) command byte figure 6. device configuration data management command byte meaning 80h disables all writes except the write_protect command. 40h disables all writes except the write_protect, operation, and page commands. 20h disables all writes except the write_protect, operation, page, and on_off_config commands. 00h enables writes for all commands (default). main configuration configuration page + x0 offset flash ram backup operating single page + x64 offset temporary pmbus control and monitoring engine max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 42 downloaded from: http:///
store_default_all (11h) the store_default_all command instructs the device to copy ram operating to the flash main memory array. not all information is stored. only configu - ration data is stored, not any status, or operational data. if an error occurs during the transfer, alert asserts if enabled and the cml bit in and status_word is set to 1. no bits are set in status_cml. this command is write-only. there is no data byte for this command. when the store_default_all command is invoked, the device is unresponsive to pmbus commands and does not monitor power supplies while transferring the configuration. the time required to complete this task is listed in the electrical characteristics . the mfr_store_ single command allows a single command to be stored in much less time. user note: v dd must be above 2.9v for the device to perform the store_default_all command. restore_default_all (12h) the restore_default_all command instructs the device to copy the flash main memory array to ram operating and ram temporary. the restore_ default_all command should only be executed when the device is not operating the power supplies. this com - mand is write-only. there is no data byte for this com - mand. when restore_default_all is issued, the data is checked for validity before being transferred. if the main array is corrupt, the device sets bit 1 of status_ cml and loads the backup copy. if the backup copy is corrupt, the device set bits 2 of status_cml and remains in a null state with all pins (except scl and sda) high impedance. the fault pin(s) is also asserted. to resolve the data corruption, the configuration data must be written to ram operating and store_default_ all must be issued followed by a device reset. table 15. memory transfer pmbus commands pmbus command resulting memory transfer store_default_all copy ram operating to lash main. restore_default_all copy lash main to ram operating and ram temporary. mfr_store_all code = 00h copy ram operating to lash main. code = 01h copy ram operating to lash backup. code = 02h copy ram temporary to lash main. code = 03h copy ram temporary to lash backup. mfr_restore_all code = 00h copy lash main array to ram operating. code = 01h copy lash backup to ram operating. code = 02h copy lash main to ram temporary. code = 03h copy lash backup to ram temporary. mfr_store_single copy ram operating (single parameter) to lash single. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 43 downloaded from: http:///
upon a device power-on reset or any device reset, this command is automatically executed by the device without pmbus action required. mfr_store_all (eeh) the mfr_store_all command instructs the device to copy ram operating or ram temporary to either the flash main memory array or the flash backup memory array. which transfer is to occur is determined by the code. this command is write-only. there is one data byte for this command which is the code. only code values of 00h to 03h are valid; all other code values are ignored. not all information is stored. only configura - tion data is stored, not any status, or operational data. if an error occurs during the transfer, alert asserts if enabled and the cml bit in and status_word is set to 1. no bits are set in status_cml. note that if the code is 00h, then this command operates the same as store_default_all. code = 00h copy ram operating to lash main code = 01h copy ram operating to lash backup code = 02h copy ram temporary to lash main code = 03h copy ram temporary to lash backup when the mfr_store_all command is invoked, the device is unresponsive to pmbus commands and does not monitor power supplies while transferring the configu - ration. the time required to complete this task is listed in the electrical characteristics . the mfr_store_single command allows a single command to be stored in much less time. user note: v dd must be above 2.9v for the device to perform the mfr_store_all command. mfr_restore_all (efh) the mfr_restore_all command instructs the device to copy either the flash main memory array or the flash backup memory array to either ram operating or ram temporary. which transfer is to occur is deter - mined by the code. this command is write-only. there is one data byte for this command which is the code. only code values of 00hC03h are valid; all other code values are ignored. note that if the code is 00h, then this com - mand operates the same as restore_default_all. the mfr_restore_all command should only be executed when the device is not operating the power supplies. code = 00h copy lash main to ram operating code = 01h copy lash backup to ram operating code = 02h copy lash main to ram temporary code = 03h copy lash backup to ram temporary when mfr_restore_all is issued, the data is checked for validity before being transferred. if the main array is corrupt, the device sets bit 1 of status_cml. if the backup array is corrupt, the device sets bit 2 of status_cml. no other action is taken by the device. to resolve the data corruption, the configuration data must be written to ram operating and store_default_ all or mfr_store_all must be issued. mfr_store_single (fch) the mfr_store_single is a read/write word com - mand that instructs the device to transfer a single con - figuration parameter from ram operating to the flash single memory array. the upper byte contains the page and the lower byte contains the pmbus command that should be stored. for example, if the ton_delay parameter for the power supply controlled by page 4 needs to stored to flash, 0460h would be written with this command. when read, this command reports the last single page/command written to flash. this command can be used while the device is operating the power supplies. if an error occurs during the transfer, alert asserts if enabled and the cml bit in status_word is set to 1. no bits are set in status_cml. the mfr_store_ single command should only be invoked a maximum of 85 times before either a device reset is issued, or a device power cycle occurs, or the restore_default_all command is invoked. once the mfr_store_single command is invoked, the store_default_all and mfr_store_all commands should not be used until either a device reset is issued, or a device power cycle occurs, or the restore_default_all command is invoked. also, mfr_store_single should not be used for commands that are not stored in flash. see table 3 for a list of commands that are stored in flash. user note: v dd must be above 2.9v for the device to perform the mfr_store_single command. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 44 downloaded from: http:///
mfr_crc (feh) the mfr_crc is a read/write word command that instructs the device to report the calculated 16-bit crc value of either the ram operating or ram temporary or flash main or flash backup memory arrays. a crc value for the flash single array is not available. only one 16-bit crc is reported with each read of mfr_crc. which crc value to be reported is determined by the most previous written code value as shown in the table 16 . for example, if mfr_crc is first written with a code of 0001h, then the next read of mfr_crc reports the crc for the flash backup array. if no code value is written, mfr_crc returns ffffh when read. capability (19h) the capability command is used to determine some key capabilities of the device. the capability com - mand is read-only. the message content is described in table 17 . vout_mode (20h) the vout_mode command is used to report the data format of the device. the device uses the direct format for all the voltage-related commands. the value returned is 40h, indicating direct data format. this command is read-only. if a host attempts to write this command, the cml status bit is asserted. see table 5 for the m, b, and r values for the various commands. vout_command (21h) the vout_command command loads the device with the voltage to which the power-supply output is to be changed to after all other power supplies in the sequence group are powered up. the device adjusts the power- supply voltage by enabling the associated dac output and actively close-loop margining the power-supply out - put voltage. after all the power supplies are powered up, the device loads the onboard dac with the dac value in the mfr_margin_config command, and begins to margin the power-supply output voltage up or down as needed. this margining runs continuously as long as the power supply is enabled. if margining is enabled using the operation command, then the vout_command is overridden and the power supply is driven to the voltage as configured in the vout_margin_high or vout_margin_low command. if vout_command is set to 0000h, the vout_command is disabled and no active power-supply output voltage adjustment is done and the dac output remains high impedance. the vout_command should only be changed when the power supplies are turned off. the 2 data bytes are in direct format. if the device cannot successfully close- loop margin the power supply, the device keeps attempt - ing to margin the supply and does the following: 1) sets the margin bit in status_word. 2) sets the margin_fault bit in status_mfr_ specific (pages 0 to 15). 3) notifies the host through alert assertion (if enabled in mfr_mode). table 16. mfr_crc (feh) command byte table 17. capability (19h) command byte mfr_crc code value memory array crc value to be reported on next read of mfr_crc 0000h flash main 0001h flash backup 0002h ram operating 0003h ram temporary bit name meaning 7 packet-error checking 0 = pec not supported. 6:5 pmbus speed 01 = maximum supported bus speed is 400khz. 4 alert 1 = device supports an alert output (alert is enabled in mfr_mode). 0 = device does not support alert output (alert is disabled in mfr_mode). 3:0 reserved always returns 0000. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 45 downloaded from: http:///
vout_margin_high (25h) the vout_margin_high command loads the device with the voltage to which the power-supply output is to be changed when the operation command is set to margin high. if the power supply is already operating at margin high, changing vout_margin_high has no effect on the output voltage. the device only adjusts the power supply to the new vout_margin_high voltage after receiving a new margin high operation com - mand. the 2 data bytes are in direct format. if the device cannot successfully close-loop margin the power supply, the device keeps attempting to margin the supply and does the following: 1) sets the margin bit in status_word. 2) sets the margin_fault bit in status_mfr_ specific (pages 0 to 15). 3) notifies the host through alert assertion (if enabled in mfr_mode). vout_margin_low (26h) the vout_margin_low command loads the device with the voltage to which the power-supply output is to be changed when the operation command is set to margin low. if the power supply is already operating at margin low, changing vout_margin_low has no effect on the output voltage. the device only adjusts the power supply to the new vout_margin_low voltage after receiving a new margin low operation command. the 2 data bytes are in direct format. if the device can - not successfully close-loop margin the power supply, the device keeps attempting to margin the supply and does the following: 1) sets the margin bit in status_word. 2) sets the margin_fault bit in status_mfr_ specific (pages 0 to 15). 3) notifies the host through alert assertion (if enabled in mfr_mode). vout_scale_monitor (2ah) in applications where the measured power-supply volt - age is not equal to the voltage at the adc input, vout_scale_monitor is used. for example, if the adc input expects a 1.8v input for a 12v output, vout_ scale_monitor = 1.8v/12v = 0.15. in applications where the power-supply output voltage is greater than the max34462 input range of 2.048v, the output voltage of the power supply is sensed through a resistive voltage- divider. the resistive voltage divider reduces or scales the output voltage. the pmbus commands specify the actual power-supply output voltages and not the input voltage to the adc. to allow the device to map between the high power-supply voltages (such as 12v) and the voltage at the adc input, the vout_scale_monitor command is used. the 2 data bytes are in direct format. this value is dimensionless. as an example, if the required scaling factor is 0.15, then vout_scale_monitor should be set to 1333h (4915/32767 = 0.15). see table 18 . user note: the devices full-scale adc voltage is 2.048v. a scaling factor where a 1.8v adc input repre - sents a nominal 100% voltage level is recommended to allow headroom for margining. resistor-dividers must be used to measure voltage greater than 1.8v. the maximum source impedance of the resistor divider is limited by the setting of the adc_time bits in mfr_mode. see the recommended operating conditions section for details. table 18. vout_scale_monitor (2ah) examples nominal voltage level monitored nominal adc input voltage level resistive divider ratio vout_scale_monitor value 1.8v or less 1.8v 1.0 7fffh 2.5v 1.8v 0.72 5c28h 3.3v 1.8v 0.545454 45d1h 5v 1.8v 0.36 2e14h 12v 1.8v 0.15 1333h max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 46 downloaded from: http:///
iout_cal_gain (38h) the iout_cal_gain command is used to set the ratio of the voltage at the adc input to the sensed current. the units of the iout_cal_gain factor are 0.1m. the 2 data bytes are in direct format. as an example, if a 10m sense resistor is used in conjunction with a 50v/v current sense amplifier, the iout_cal_gain should be set to 500m or 1388h. user note: the devices full-scale adc voltage is 2.048v. the value of the sense resistor and current- sense amplifier gain must be scaled appropriately. also, the maximum voltage at the rs inputs must be less than 4v. the maximum output impedance of the current sense amplifier is limited by the setting of the adc_time bits in mfr_mode. see the recommended operating conditions section for details. vout_ov_fault_limit (40h) the vout_ov_fault_limit command sets the value of the output voltage which causes an output overvoltage fault. the monitored voltage must drop by at least 2% below the limit before the fault is allowed to clear. the 2 data bytes are in direct format. in response to the vout_ov_fault_ limit being exceeded, the device does the following: 1) sets the vout_ov bit and the vout bit in status_ word. 2) sets the vout_ov_fault bit in status_vout. 3) responds as specified in the mfr_fault_response. 4) notifies the host through alert assertion (if enabled in mfr_mode). vout_ov_warn_limit (42h) the vout_ov_warn_limit command sets the value of the output voltage which causes an output voltage high warning. the monitored voltage must drop by at least 2% below the limit before the warning is allowed to clear. this value is typically less than the output overvoltage thresh - old in vout_ov_fault_limit. the 2 data bytes are in direct format. in response to the vout_ov_warn_ limit being exceeded, the device does the following: 1) sets the vout bit in status_word. 2) sets the vout_ov_warn bit in status_vout. 3) notifies the host using alert assertion (if enabled in mfr_mode). vout_uv_warn_limit (43h) the vout_uv_warn_limit command sets the value of the output voltage which causes an output-voltage low warning. the monitored voltage must increase by at least 2% above the limit before the warning is allowed to clear. this value is typically greater than the output undervolt - age fault threshold in vout_uv_fault_limit. this warning is masked until the output voltage reaches the programmed power_good_on for the first time and also during turn-off when the power supply is disabled. if the voltage is being monitored, this should be set to a value greater than 100mv. the 2 data bytes are in direct format. in response to violation of the vout_ uv_warn_limit, the device does the following: 1) sets the vout bit in status_word. 2) sets the vout_uv_warn bit in status_vout. 3) notifies the host using alert assertion (if enabled in mfr_mode). vout_uv_fault_limit (44h) the vout_uv_fault_limit command sets the value of the output voltage which causes an output undervolt - age fault. the monitored voltage must increase by at least 2% above the limit before the fault is allowed to clear. this fault is masked until the output voltage reaches the pro - grammed power_good_on for the first time and also during turn-off when the power supply is disabled. if the voltage is being monitored, this should be set to a value greater than 100mv. the 2 data bytes are in direct format. in response to violation of the vout_uv_fault_ limit, the device does the following: 1) sets the vout bit in status_word. 2) sets the vout_uv_fault bit in status_vout. 3) responds as specified in mfr_fault_response. 4) notifies the host using alert assertion (if enabled in mfr_mode). iout_oc_warn_limit (46h) the iout_oc_warn_limit command sets the value of the current which causes an overcurrent warning. the monitored current must decrease by at least 5% below the limit before the warning is allowed to clear. this value is typically less than the overcurrent fault thresh - old in iout_oc_fault_limit. the 2 data bytes are in direct format. in response to violation of the iout_oc_ warn_limit, the device does the following: 1) sets the iout bit in status_word. 2) sets the iout_oc_warn bit in status_iout. 3) notifies the host using alert assertion (if enabled in mfr_mode). max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 47 downloaded from: http:///
iout_oc_fault_limit (4ah) the iout_oc_fault_limit command sets the value of the current which causes an overcurrent fault. the moni - tored current must decrease by at least 5% below the limit before the fault is allowed to clear. this fault is masked until the current is below this limit for the first time. the 2 data bytes are in direct format. in response to violation of the iout_oc_fault_limit, the device does the following: 1) sets the iout bit in status_word. 2) sets the iout_oc_fault bit in status_iout. 3) responds as specified in the mfr_fault_response. 4) notifies the host using alert assertion (if enabled in mfr_mode). ot_fault_limit (4fh) the ot_fault_limit command sets the temperature, in degrees celsius, of the selected temperature sensor at which an overtemperature fault is detected. the moni - tored temperature must drop by at least 4c below the limit before the fault is allowed to clear. the 2 data bytes are in direct format. in response to the ot_fault_ limit being exceeded, the device does the following: 1) sets the temperature bit in status_word. 2) sets the ot_fault bit in status_temperature register. 3) responds as specified in the mfr_fault_response. 4) notifies the host using alert assertion (if enabled in mfr_mode). ot_warn_limit (51h) the ot_warn_limit command sets the temperature, in degrees celsius, of the selected temperature sensor at which an overtemperature warning is detected. the moni - tored temperature must drop by at least 4c below the limit before the warning is allowed to clear. the 2 data bytes are in direct format. in response to the ot_warn_limit being exceeded, the device does the following: 1) sets the temperature bit in status_word. 2) sets the ot_warn bit in status_temperature register. 3) notifies the host through alert assertion (if enabled in mfr_mode). power_good_on (5eh) the power_good_on command sets the value of the output voltage which the channel must exceed for a power-good state to be declared on this chan - nel. all power supplies must also be above power_ good_on for power-supply margining to begin. the power_good_on threshold is also used to deter - mine if the ton_max_fault_limit is exceeded. the power_good_on level is normally set higher than the power_good_off level. the 2 data bytes are in direct format. power_good_off (5fh) the power_good_off command sets the value of the output voltage which causes the power-good state on this channel to deassert after it has been asserted. the power_good_off level is normally set lower than the power_good_on level. the 2 data bytes are in direct format. when the vout level of a power supply falls from greater than power_good_on to less than power_good_ off, the device does the following: 1) sets the power_good# in status_word. 2) sets the power_good# bit in status_mfr_ specific register (pages 0 to 15). ton_delay (60h) in the pmbus sequencing configuration, ton_delay sets the time, in milliseconds, from when a start condition is received until the psen output is asserted. if the psen/ gpo output has been configured (with the mfr_psen_ config command) as a pg/gpi or alarm pin, then this command can be used to delay the assertion of the output. the 2 data bytes are in direct format. toff_delay (64h) the toff_delay sets the time, in milliseconds, from when a stop condition is received (a soft-off operation command or through the control0/1/2/3 pins when enabled) until the psen output is deasserted. when commanded to turn off immediately (either through the operation command or the control0/1/2/3 pins), the toff_delay value is ignored. if the psen/gpo out - put has been configured (with the mfr_psen_config command) as a pg/gpi or alarm pin, then this com - mand can be used to delay the deassertion of the output. the 2 data bytes are in direct format. user note: when ton_delay and toff_delay are used to delay the psen/gpo outputs for power- good or alarm signals, the actual time delays are 2ms to 3ms longer than configured due to processing delays within the device. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 48 downloaded from: http:///
note: the setting of the sys_off and power_good# bits do not assert the alert signal. ton_max_fault_limit (62h) the ton_max_fault_limit sets an upper time limit, in milliseconds, from when the psen output is asserted until the output voltage crosses the power_good_on threshold. the 2 data bytes are in direct format. if the value is zero, then the limit is disabled. in response to the ton_max_fault_limit being exceeded, the device does the following: 1) sets the vout bit in status_word. 2) sets the ton_max_fault bit in status_vout. 3) responds as specified in the mfr_fault_response. 4) notifies the host using alert assertion (if enabled in mfr_mode). status_word (79h) the status_word command returns 2 bytes of information with a summary of the reason for a fault. the status_word message content is described in table 19 . table 19. status_word (79h) bit name meaning 15 vout an output voltage fault or warning, or ton_max_fault_limit or mfr_ton_seq_max has occurred. 14 iout an overcurrent fault or warning has occurred. 13 0 this bit always returns a 0. 12 mfr a bit in status_mfr_specific (page = 255) has been set. 11 power_good# any power-supply voltage has fallen from power_good_on to less than power_good_off (logical or of all the power_good# bits in status_mfr_specific). 10:9 0 these bits always return a 0. 8 margin a margining fault has occurred. 7 0 this bit always returns a 0. 6 sys_off set when any of the power supplies are sequenced off (logical or of all the off bits in status_mfr_specifc). 5 vout_ov an overvoltage fault has occurred. 4 iout_oc an overcurrent fault has occurred. 3 0 this bit always returns a 0. 2 temperature a temperature fault or warning has occurred. 1 cml a communication, memory, or logic fault has occurred. 0 0 this bit always returns a 0. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 49 downloaded from: http:///
figure 7. status register organization vout_ov_fault status_vout (pages 0C15) latch event fault_log_full status_cml (all pages) event data_fault latch event comm_fault latch event main_fault latch event backup_fault latch event vout_ov_warn latch event vout_uv_fault or or or and clear or status_temperature (pages 16C20) ot_warn event ot_fault latch latch event status_iout (pages 0C15) oc_fault latch event oc_warn latch event oror or status_mfr_specific (page 0C15) off event power_good# event margin_fault latch event status_mfr_specific (pages 255) lock event control# latch event sync latch event watchdog latch event fault_input latch event latch event vout_uv_warn latch event ton_max_fault latch event status_word (all pages) latch temperature sys_off power_good# vout_ov vout cml iout_oc iout margin mfr clear_faults command alert response address (ara) received and arbitration won alert bit in mfr_mode alert output note 1: if an event is still present when the clear_faults command is issued, the bit is immediately asserted once again. note 2: when the alert latch is cleared, if any events are still present, they do not reassert the alert output. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 50 downloaded from: http:///
status_vout (7ah) the status_vout command returns one byte of infor - mation with contents as described in table 20 . all the bits in status_vout are latched. when cleared, the bits are set again if the condition persists or in the case of ton_max_fault, when the event occurs again. status_iout (7bh) the status_iout command returns one byte of infor - mation with contents as described in table 21 . all the bits in status_iout are latched. when cleared, the bits are set again if the condition persists. status_temperature (7dh) the status_temperature command returns one byte of information with contents as described in table 22 . all the bits in status_vout are latched. when cleared, the bits are set again if the condition persists. table 20. status_vout (7ah) table 21. status_iout (7bh) table 22. status_temperature (7dh) bit name meaning latched 7 vout_ov_fault vout overvoltage fault. yes 6 vout_ov_warn vout overvoltage warning. yes 5 vout_uv_warn vout undervoltage warning. yes 4 vout_uv_fault vout undervoltage fault. yes 3 0 this bit always returns a 0. 2 ton_max_fault ton maximum fault or mfr_ton_seq_max fault. yes 1:0 0 these bits always return a 0. bit name meaning latched 7 iout_oc_fault iout overcurrent fault. yes 6 0 this bit always returns a 0. 5 iout_oc_warn iout overcurrent warning. yes 4:0 0 these bits always return a 0. bit name meaning latched 7 ot_fault overtemperature fault. yes 6 ot_warn overtemperature warning. yes 5:0 0 these bits always return a 0. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 51 downloaded from: http:///
note 1: when nv fault log overwrite is enabled (nv_log_overwrite = 1 in mfr_mode), fault_log_full is set wh en the fault log is full, but clears when the fault log is overwritten since two fault logs are cleared before each overwrite. note 2: the setting of the backup_fault and main_fault bits do not assert the alert signal. note 1: the setting of the off and power_good# bits do not assert the alert signal. note 2: when an input channel is configured as a gpi input using the mfr_channel_config command, the power_ good# bit is set when the gpi input is deasserted. status_cml (7eh) the status_cml command returns one byte of informa - tion with contents as described in table 23 . the comm_ fault, data_fault, main_fault, and backup_ fault bits are latched. when cleared, the bits are set again when the event occurs again. the fault_log_ full bit reflects the current real-time state of the fault log. status_mfr_specific (80h) the status_mfr_specific message content var - ies based on the selected page and it is described in table 24 and table 25 . table 23. status_cml (7eh) table 24. status_mfr_specific (80h) (for pages 0 to 15) bit name meaning latched 7 comm_fault an invalid or unsupported command has been received. yes 6 data_fault an invalid or unsupported data has been received. yes 5:3 0 these bits always return a 0. 2 backup_fault flash backup memory array is corrupt. yes 1 main_fault flash main memory array is corrupt. yes 0 fault_log_full mfr_nv_fault_log is full and needs to be cleared. no bit name meaning latched 7 off for enabled channels, this bit relects the output state of the sequencer and is set when psen is not asserted due to either a sequencing delay or a fault, or the power supply being turned off. this bit is always cleared when the channel is disabled. if psen is reconigured as a gpo, this bit does not relect the state of the pin (note 1). no 6:4 0 these bits always return a 0. 3 margin_fault this bit is set if the device cannot properly close-loop margin the power supply. yes 2 power_good# this bit is set when the power-supply voltage has fallen from power_good_on to less than power_good_off. on device reset, this bit is set until the power supply is greater than power_good_on (notes 1 and 2). no 1:0 0 these bits always return a 0. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 52 downloaded from: http:///
note 1: the setting of the lock bit does not assert the alert signal. note 2: applies to all fault inputs. the fault status bit is set even if the fault pin is configured in mfr_nv_log_config to ignore the fault pins. if a fault pin is used as a gpo, it does not affect this bit. note 3: any control pin can set this bit. on_off_config must be configured to use the control0/1/2/3 pins f or this status bit to function. read_vout (8bh) the read_vout command returns the actual measured (not commanded) output voltage. read_vout is mea - sured and updated every 5ms. if the rs/gpi is configured to be a general-purpose input (gpi) by configuring the select bits in mfr_channel_config to either 30h or 34h, then read_vout reports 0000h when the gpi input is inactive and 0001h when the gpi input is active. the 2 data bytes are in direct format. read_iout (8ch) the read_iout command returns the latest measured current value. read_iout is measured and updated every 5ms. the 2 data bytes are in direct format. read_temperature_1 (8dh) the read_temperature_1 command returns the temperature returned from the temperature sensor. read_temperature_1 returns 7fffh if the sensor is faulty and 0000h if the sensor is disabled. read_ temperature_1 is measured and updated once a second. the 2 data bytes are in direct format. pmbus_revision (98h) the pmbus_revision command returns the revision of the pmbus specification to which the device is compli - ant. the command has 1 data byte. bits [7:4] indicate the revision of pmbus specification part i to which the device is compliant. bits [3:0] indicate the revision of pmbus specification part ii to which the device is compliant. this command is read-only. the pmbus_revision value returned is always 11h which indicates that the device is compliant with part i rev 1.1 and part ii rev 1.1. mfr_id (99h) the mfr_id command returns the text (iso/iec 8859-1) character of the manufacturers (maxim) identification. the default mfr_id value is 4dh (m). this command is read-only. mfr_model (9ah) the mfr_model command returns the text (iso/iec 8859-1) character of the device model number. the default mfr_model value is 5ah (z). this command is read-only. mfr_revision (9bh) the mfr_revision command returns two text (iso/ iec 8859-1) characters that contain the device revision numbers for hardware (upper byte) and firmware (lower byte). this command is read-only. mfr_location (9ch) the mfr_location command loads the device with text (iso/iec 8859-1) characters that identify the facil - ity that manufactures the power supply. the maximum number of characters is 8. this data is written to internal flash using the store_default_all command. the factory-default text string value is 10101010. table 25. status_mfr_specific (80h) (for page 255) bit name meaning latched 7 lock set when the device is password protected (note 1). no 6 fault_input set each time any of the fault inputs is pulled low (note 2). yes 5 0 this bit always returns a 0. 4 watchdog_int set upon device reset when the internal watchdog has caused the device reset. yes 3 control# set each time the control0/1/2/3 inputs are deasserted (note 3). yes 2:1 0 these bits always return a 0. 0 sync set when the sync input (slave mode only) is not toggling. yes max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 53 downloaded from: http:///
mfr_date (9dh) the mfr_date command loads the device with text (iso/iec 8859-1) characters that identify the date of manufacture of the power supply. the maximum number of characters is 8. this data is written to internal flash using the store_default_all command. the factory default text string value is 10101010. mfr_serial (9eh) the mfr_serial command loads the device with text (iso/iec 8859-1) characters that uniquely identify the device. the maximum number of characters is 8. this data is written to internal flash using the store_ default_all command. the factory default text string value is 10101010. the upper 4 bytes of mfr_serial are used to unlock a device that has been password pro - tected. the lower 4 bytes of mfr_serial are not used to unlock a device and they can be set to any value. mfr_mode (d1h) the mfr_mode command is used to configure the device to support manufacturer specific commands. the mfr_mode command should not be changed while power supplies are operating. the mfr_mode com - mand is described in table 26 . table 26. mfr_mode (d1h) bit name meaning 15:14 0 these bits always return a 0. 13 alert 0 = alert disabled (device does not respond to ara). 1 = alert enabled (device does respond to ara). 12 sync sync pin select. 0 = master (sync pin outputs a 20khz clock) 1 = slave (sync pin inputs a 20khz clock) 11 soft_reset this bit must be set, then cleared and set again within 8ms for a soft reset to occur. 10 lock this bit must be set, then cleared and set again within 8ms for the device to become password protected. this bit is cleared when the password is unlocked. the device should only be locked and then unlocked a maximum of 256 times before either a device reset is issued or a device power cycle occurs. 9:8 0 these bits always return a 0. 7:6 adc_time[1:0] these bits select the adc conversion time: adc_time[1:0] 0001 10 11 adc conversion time 1s2s 4s 8s 5:4 adc_average[1:0] these bits select the post adc conversion averaging: adc_average[1:0] 0001 10 11 adc averaging no averaging average 2 samples average 4 samples average 8 samples 3:0 iout_avg[3:0] these bits determine the number of samples to average before reporting the value in mfr_iout_avg: iout_avg[3:0] 00000001 0010 0011 01000101 0110 0111 averaging 1 sample 2 samples4 samples 8 samples 16 samples32 samples 64 samples 128 samples iout_avg[3:0] 10001001 1010 1011 1100 1101 1110 1111 averaging 256 samples512 samples 1024 samples2048 samples 4096 samples 8192 samples 16,384 samples 32,768 samples max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 54 downloaded from: http:///
*for proper sequencing, the select bits in mfr_channel_config must be set to 10h. mfr_psen_config (d2h) the mfr_psen_config command is used to configure the individual psenx/gpox (x = 0 to15) outputs. all the psen outputs are open drain and 5v tolerant. this com - mand should not be changed while the power supplies are operating. the mfr_psen_config command is described in table 27 and figure 8 . each psen/gpo pin can be independently configured using the select[2:0] bits to one of the following: enable and disable power supplies (select[2:0] = 000) force pin assertion (select[2:0] = 001) force pin deassertion (select[2:0] = 010) assert when all enabled channel power-good (pg) or gpi are asserted (select[2:0] = 011) assert when any enabled alarm goes active (select[2:0] = 100) if the psen/gpo output is configured to enable and dis - able power supplies (select[2:0] = 000), then the associ - ated input channel must also be configured to monitor volt - age and to sequence by setting the select bits in mfr_ channel_config to 10h. see the mfr_channel_ config command description for more details. also each psen/gpo pin can be independently configured to be either active high or active low using the hi_lo bit. if select[2:0] = 011, the psen/gpo output is config - ured to assert when some combination of power-goods (pg) and general purpose inputs (gpi) from each channel are asserted. which channels should be used in this com - bination are selected using the pg_gpi_select bits (bit 16 to 31). if the pg_gpi_select bit is cleared, then the associated channel is not used in the logical combination to assert the gpo output. if the pg_gpi_select bit is set, then the power-good or gpi from this channel is used in the logical combination to assert the gpo output. this function is useful in creating system power-good signals. table 27. mfr_psen_config (d2h) bit name meaning 31:16 pg_gpi_select alarm_select these bits are only used if select[2:0] = 011 or 100. each bit corresponds to one channel (device channel n + 16 = bit number): select[2:0] bit function 011 when this bit is cleared, the power-good (pg) or gpi from channel n is not used in the logical and to assert the gpo output. when this bit is set, the pg or gpi is used. 100 when this bit is cleared, the alarm from channel n is blocked from the logical or to assert the gpo output. when this bit is set, the alarm signal is routed to the logical or. 15:7 0 these bits always return a 0. 6 hi_lo 0 = psen/gpo active low1 = psen/gpo active high 5:3 0 these bits always return a 0. 2:0 select[2:0] these bits determine the function selected on the pin: select[2:0] 000001 010 011 100101 110 111 psenn/gpon pin function selected psen operation.* force gpo assertion. force gpo deassertion. pg/gpi operation (use bits 31:16). alarm operation (use bits 31:16). reserved reserved. reserved. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 55 downloaded from: http:///
if select[2:0] = 100, the psen/gpo output is configured to assert when any of the enabled channel alarms goes active. the channel alarms are enabled with the alarm_ select bits (bit 16 to 31). if the alarm_select bit is cleared, then the alarm from this channel is blocked. if the alarm_select bit is set, then the alarm from this chan - nel is routed to an or function such that any enabled alarm asserts the gpo output. the alarm function is chosen with the alarm_config bits in the mfr_fault_response command. this function is useful in system debug or for enabling system status leds. delay function if a delay is configured (either on or off), the input must be continuously static through the delay time before the output changes state. see figure 9 . figure 8. mfr_psen_config functional logic figure 9. input to output delay action force gpo assertion force gpo deassertion ton_delay toff_delay or or and 16 16 16 16 16 16 000 001 010 100 011 note: signals listed in italics are internal signals that connect to other devi ce functions. shaded blocks are pmbus commands. psenx (x = 0C 15) select alarm0 C alarm15 and and pg 0/ gpi0 C pg1 5 /gpi15 bits 16 C 31 bits 0 C2 bit 6 mfr_psen_config not available for force gpo assertion or deassertion active high/low psen x /gpox (x = 0C15) input output on delay on delay off delay off delay max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 56 downloaded from: http:///
mfr_vout_peak (d4h) the mfr_vout_peak command returns the maximum actual measured output voltage. to reset this value to 0, write to this command with a data value of 0. any values written to this command are used as a comparison for future peak updates. the 2 data bytes are in direct format. mfr_iout_peak (d5h) the mfr_iout_peak command returns the maximum actual measured current. to reset this value to 0, write to this command with a data value of 0. any values written to this command are used as a comparison for future peak updates. the 2 data bytes are in direct format. mfr_temperature_peak (d6h) the mfr_temperature_peak command returns the maximum measured temperature. to reset this value to its lowest value, write to this command with a data value of 8000h. any other values written by this command are used as a comparison for future peak updates. the 2 data bytes are in direct format. mfr_vout_min (d7h) the mfr_vout_min command returns the minimum actual measured output voltage. to reset this value, write to this command with a data value of 7fffh. any values written to this command are used as a comparison for future minimum updates. the 2 data bytes are in direct format. mfr_iout_avg (e2h) the mfr_iout_avg command returns the calculated average current. the number of samples collected in the average before reporting the value in mfr_iout_avg is configured using the iout_avg bits in mfr_mode. writes to this command are ignored. the 2 data bytes are in direct format. mfr_nv_log_config (d8h) the mfr_nv_log_config command is used to con - figure the operation of the nonvolatile fault logging in the device. the mfr_nv_log_config command is described in table 28 . table 28. mfr_nv_log_config (d8h) bit name meaning 15 force_nv_fault_log setting this bit to 1 forces the device to log data into the nonvolatile fault log. once set, the device clears this bit when the action is completed. host must set again for subsequent action. if an error occurs during this action, the device sets the cml bit in status_word; no bits are set in status_cml. 14 clear_nv_fault_log setting this bit to 1 forces the device to clear the nonvolatile fault log by writing ffh to all byte locations. once set, the device clears this bit when the action is completed. host must set again for subsequent action. if an error occurs during this action, the device sets the cml bit in status_word; no bits are set in status_cml. while clearing the fault log, monitoring is stopped and commands should not be sent to the pmbus port. 13:11 0 these bits always return a 0. 10 nv_log_t0_config this bit determines the source of the data written into the t0 location of each page when a nonvolatile fault log is written. 0 = log the last regular collection interval adc reading 1 = read the latest adc value before logging 9 nv_log_overwrite 0 = do not overwrite the nv fault log1 = overwrite the nv fault log once it is full* 8:7 nv_log_depth[1:0] these bits determine the depth of the nv fault log: nv_log_depth[1:0] 0001 10 11 adc result collection interval 5ms 20ms80ms 160ms nv fault log depth 15ms60ms 240ms480ms max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 57 downloaded from: http:///
*the device clears two fault logs at a time when overwrite is enabled. mfr_fault_response (d9h) the mfr_fault_response command specifies the response to each fault or warning condition supported by the device. in response to a fault/warning, the device always reports the fault/warning in the appropriate sta - tus register and asserts the alert output (if enabled in mfr_mode). a cml fault cannot cause any device action other than setting the status bit and asserting the alert output. the mfr_fault_response command is described in table 30 and figure 10 . for each fault type (overvoltage or overcurrent, under - voltage, sequencing error, and overtemperature), each channel can be independently configured to respond in the required manner with the response bits in mfr_ fault_response ( table 29 ). if channels 0 to 15 are configured to latchoff for a particular fault, the channel turns off (either immediately or after the toff_delay as configured or commanded) and also asserts one or more of the fault pins if they are enabled with bits 16 to 19 in mfr_fault_response. the channel remains off and the fault outputs remain asserted until either the master power control is toggled using the operation command or control0/1/2/3 pins as configured in the on_off_config command or the device is reset or power cycled. when the device attempts to sequence the power supplies on, all enabled faults must be cleared before the channel is allowed to power-on or the fault pins be deasserted. if the channel is configured to retry for a particular fault, the channel turns off (either immediately or after the toff_delay as configured or commanded) and also asserts one or more the fault pins if they are enabled with bits 16 to 19 in mfr_fault_response. the channel remains off and the fault outputs remain asserted for the time configured in mfr_fault_retry. after the time in mfr_fault_retry expires, the device attempts to sequence the power supplies back on as long as all the enabled faults in the channel are cleared. if all the enabled faults are cleared, the device deasserts all the fault pins it asserted, and the power-up sequencing begins, as long as no other channels have asserted the fault pins it has been configured to monitor with bits 24 to 27 in mfr_fault_response. global channels must assert a fault pin and respond to that fault pin in order for the channel to shut down. local vs. global channels with the mfr_fault_response command (bit 14), each power-supply channel can be tagged as either being local or global. when bit 14 is cleared, the channel is configured as a local channel which means that a detected fault only affects this channel (or page). with the response bits in the mfr_fault_response command, the device can be configured to respond dif - ferently to each possible fault. when bit 14 is set, the channel is configured as a global channel which means that a detected fault on this channel can assert all enabled fault outputs. which fault outputs are enabled is selected with bits 16 to 19. only global channels respond to fault pins that are asserted. which fault pins the channel should respond to is assigned with bits 24 to 27. local channels do not respond to the fault pins. table 28. mfr_nv_log_config (d8h) (continued) bit name meaning 6 nv_log_fault0 0 = do not write nv fault log when fault0 pin is externally pulled low. 1 = write nv fault log when fault0 pin is externally pulled low and the fault0 pin is enabled. 5 nv_log_fault1 0 = do not write nv fault log when fault1 pin is externally pulled low. 1 = write nv fault log when fault1 pin is externally pulled low and the fault1 pin is enabled. 4 nv_log_fault2 0 = do not write nv fault log when fault2 pin is externally pulled low. 1 = write nv fault log when fault2 pin is externally pulled low and the fault2 pin is enabled. 3 nv_log_fault3 0 = do not write nv fault log when fault3 pin is externally pulled low. 1 = write nv fault log when fault3 pin is externally pulled low and the fault3 pin is enabled. 2:0 0 these bits always return a 0. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 58 downloaded from: http:///
note: device response to faults is determined by the configuration of mfr_fault_response. global channels respond to fault assertion bits 24 to 27 in the mfr_fault_response command are used to configure global channels to respond or ignore one or more of the fault pins when they are asserted. when one or more of the enabled fault pins are asserted, the channel either deasserts the psen output immediately or after the toff_delay according to the configuration of bit 0 in the on_off_config command. the channel continues to deassert the psen output until all enabled fault pins deassert. when all enabled fault pins deassert, the channel sequences on as configured if no channel faults are present. temperature fault response a temperature fault is declared when any of the enabled temperature sensors detects a fault. a temperature fault acts globally and can affect all the power supplies. for all global supplies, the worse-case fault response of all global channels is applied. if this response is latchoff or retry, all fault pins that are programmed to be asserted by any of the global channels are asserted. all local chan - nels respond independently as programmed in that chan - nels mfr_fault_response. fault detection before power-on sequencing before any power-supply channel is enabled or fault output is deasserted, the device checks for overvolt - age, overcurrent, and overtemperature faults (but not for undervoltage) if the channel is configured for a fault response to either latch-off (response[1:0] = 01) or retry (response[1:0] = 10) in the mfr_fault_repsonse command. undervoltage faults are detected when the power supply turns on and fails to reach the power-good level; the ton_max_fault_limit is exceeded and the device takes fault action as configured. logging faults into mfr_nv_fault_log if bit 15 of mfr_fault_response is set, faults are logged into the on-board nonvolatile fault log for this chan - nel unless the response for the associated fault is config - ured to take no action (response[1:0] = 00). to keep from needlessly filling the fault log with excessive data, the following rules are applied when subsequent faults occur. when overvoltage faults occurs, subsequent over - voltage faults on this channel are not written to the fault log until either the clear_faults command is issued or a device reset occurs. the same rule applies to over - current, undervoltage, overtemperature, and sequencing faults. see table 30 and figure 10 . table 29. fault-monitoring states fault required device configuration for active monitoring when monitored overvoltage ? voltage monitoring enabled (select[5:0] = 10h or 20h in mfr_channel_config) continuous monitoring undervoltage ? voltage monitoring enabled (select[5:0] = 10h or 20h in mfr_channel_config) stop monitoring while the power supply is off; start monitoring when voltage exceeds the power_good_on level overcurrent ? current monitoring enabled (select[5:0] = 22h in mfr_channel_config) continuous monitoring power-up time ? sequencing enabled (select[5:0] = 10h in mfr_channel_config) monitored only during power-on sequence overtemperature ? temperature sensor enabled (enable = 1 in mfr_temp_sensor_config) continuous monitoring max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 59 downloaded from: http:///
note 1: channels configured to monitor current must be configured as global. note 2: the filter selection does not apply to temperature or sequencing faults. note 3: all enabled temperature sensor faults are logically ored together. note 4: if the channel is configured to measure current, these bits are ignored. note 5: depends on whether the channel is configured to monitor voltage or current. table 30. mfr_fault_response (d9h) bit name meaning 31:28 0 these bits always return a 0. 27 fault3_response_enable 0 = fault3 response disabled 1 = fault3 response enabled 26 fault2_response_enable 0 = fault2 response disabled 1 = fault2 response enabled 25 fault1_response_enable 0 = fault1 response disabled 1 = fault1 response enabled 24 fault0_response_enable 0 = fault0 response disabled 1 = fault0 response enabled 23:20 0 these bits always return a 0. 19 fault3_assert_enable 0 = fault3 assertion disabled 1 = fault3 assertion enabled 18 fault2_assert_enable 0 = fault2 assertion disabled 1 = fault2 assertion enabled 17 fault1_assert_enable 0 = fault1 assertion disabled 1 = fault1 assertion enabled 16 fault0_assert_enable 0 = fault0 assertion disabled 1 = fault0 assertion enabled 15 nv_log 0 = do not log the fault into mfr_nv_fault_log 1 = log the fault into mfr_nv_fault_log 14 global 0 = local (affect only the selected page) 1 = global (note 1) 13:12 filter[1:0] continuous excursion time before a fault or warning is declared and action is taken (note 2). 00 = immediate 01 = 2ms 10 = 3ms 11 = 4ms 11 0 this bit always returns a 0. 10:8 alarm_config[2:0] see table 31. 7:6 ot_fault_limit_response[1:0] see tables 32 and 33 (note 3). 5:4 ton_max_fault_limit_response[1:0] (also applies to mfr_ton_seq_max) see tables 32 and 33 (note 4). 3:2 vout_uv_fault_limit_response[1:0] see tables 32 and 33 (note 4). 1:0 vout_ov_fault_limit_response[1:0] iout_oc_fault_limit_response[1:0] see tables 32 and 33 (note 5). max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 60 downloaded from: http:///
figure 10. mfr_fault_response operation table 31. alarm_config codes alarm_config[2:0] alarm condition alarm criteria 000 none 001 sequencing fault fault only 010 undervoltage only fault only 011 undervoltage only fault or warning 100 overvoltage/overcurrent only fault only 101 overvoltage/overcurrent only fault or warning 110 undervoltage or overvoltage/overcurrent fault only 111 undervoltage or overvoltage/overcurrent fault or warning note: signals listed in italics are internal signals that connect to other devi ce functions. shaded blocks are pmbus commands. bits 13:12 bits 10:8 bits 7:0 bit 15 bit 14 bit 16 bit 18 bit 17 bit 19 16 alarm0Calarm15 local0 C local15 and or fault3 fault2 fault1 overvoltage overcurrent undervoltage sequencing error over- temperature monitoring 16 channels filter filter 01 (latch off) latch off or retry and nv log or ov/ oc 10 (retry) 11 (log only) 01 (latch off) uv seq ot and or 10 (retry) 11 (log only) 01 (latch off) 10 (retry) 11 (log only) 01 (latch off) 10 (retry) 11 (log only) internal ds75lv ds75lv ds75lv ds75lv alarm_config fault response mfr_fault_retry mfr_fault_response mfr _ nv_fault_ log global/ local select 16 and or select gpo30 16 and or select gpo31 fault3 gpo31 fault2 gpo30 fault1 gpo29 fault0 select gpo29 16 and or fault0 gpo28 select gpo28 mfr_gpo_config max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 61 downloaded from: http:///
note 1: alert is asserted if enabled when a new status bit is set. a status bit is latched when a particular fault occurs that causes a fault response. note 2: fault-free does not include undervoltage. note 1: alert is asserted if enabled when a new status bit is set. a status bit is latched when a particular fault occurs that causes a fault response. note 2: fault-free does not include undervoltage. alarm output functionality any of the gpo pins can be configured to output the alarm signals. see the mfr_dac_config, mfr_ gpo_config and mfr_psen_config commands for details. when an undervoltage or overvoltage/overcurrent alarm is occurring, the output remains asserted as long as the alarm continues. when a sequencing fault occurs, the alarm pin remain asserted until either a clear_faults command is received or master power control-off input is received with either the operation command or the control pins. table 32. mfr_fault_response codes for global channels table 33. mfr_fault_response codes for local channels response[1:0] fault response 11 ? sets the corresponding fault bit in the appropriate status register (note 1). ? logs fault into mfr_nv_fault_log if nv_log = 1. ? continues operation. 10 (retry) ? asserts all enabled fault outputs. ? sets the corresponding fault bit in the appropriate status register (note 1). ? logs fault into mfr_nv_fault_log if nv_log = 1. ? waits for the time conigured in mfr_fault_retry and then deasserts the fault outputs that were asserted if fault-free (note 2). 01 (latchoff) ? asserts all enabled fault outputs. ? sets the corresponding fault bit in the appropriate status register (note 1). ? logs fault into mfr_nv_fault_log if nv_log = 1. 00 ? sets the corresponding fault bit in the appropriate status register (note 1). ? continues operation without any action. response[1:0] fault response 11 ? sets the corresponding fault bit in the appropriate status register (note 1). ? logs fault into mfr_nv_fault_log if nv_log = 1. ? continues operation. 10 (retry) ? shuts down the power supply by deasserting the psen output. ? sets the corresponding fault bit in the appropriate status register (note 1). ? logs fault into mfr_nv_fault_log if nv_log = 1. ? waits for the time conigured in mfr_fault_retry and restarts the supply if fault-free (note 2). 01 (latchoff) ? latches off the power supply by deasserting the psen output. ? sets the corresponding fault bit in the appropriate status register (note 1). ? logs fault into mfr_nv_fault_log if nv_log = 1. 00 ? sets the corresponding fault bit in the appropriate status register (note 1). ? continues operation without any action. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 62 downloaded from: http:///
mfr_fault_retry (dah) the mfr_fault_retry command sets the delay time between a fault occurring, which results in a power supply being shut down for retry and the power supply restarting. this command value is used for all fault responses that require delay retry. the retry timer starts when the fault occurs. if the faulty channel has been configured to assert one or more fault pins, the fault pins are asserted until the retry timer expires and then they are allowed to deassert as long as no enabled faults are still present and no other channel that shares the same fault pins have not also asserted. mfr_fault_retry should be configured with a value larger than the largest system toff_delay. the 2 data bytes are in direct format. mfr_nv_fault_log (dch) each time the mfr_nv_fault_log command is exe - cuted, the device returns a block of 255 bytes contain - ing one of the 15 nonvolatile fault logs. the mfr_nv_ fault_log command must be executed 15 times to dump the complete nonvolatile fault log. if the returned fault log is all ffs (except bytes 0 and 1), this indicates that this fault log has not been written by the device. as the device is operating, it is reading the latest operating conditions for voltage, current and temperature and it is updating the status registers. all this information is stored in on-board ram. when a fault is detected (if so enabled in mfr_fault_response), the device automatically logs this information to one of the 15 nonvolatile fault logs. after 15 faults have been written, bit 0 of status_ cml is set and the device can be configured (with the nv_log_overwrite bit in mfr_nv_log_config) to either stop writing additional fault logs or to write over the oldest data. the host can clear the fault log by setting the clear_nv_fault_log bit in mfr_nv_log_ config. if a power supply is not enabled to measure voltage, current or if a temperature sensor is disabled, the associated fault log position returns 0000h (see figure 11 ). there is a fault_log_count (16-bit counter) at the beginning of each fault log that indicates which fault log is the latest. this counter rolls over should more than 65535 faults be logged. this counter is not cleared when the clear_nv_fault_log bit in mfr_nv_log_config is toggled. the 255 bytes returned by the mfr_nv_ fault_log command are described in table 34 . if an error occurs while the device is attempting to write or clear the mfr_nv_fault_log, the device sets the cml bit in status_word; no bits are set in status_ cml. alert is asserted (if enabled in mfr_mode). user note: v dd must be above 2.9v for the device to clear or log data into mfr_nv_fault_log. figure 11. mfr_nv_fault_log ram fault_log_index fault_log_count mfr_time_count status_word status_vout/status_iout status_mfr_specific status_cml status_temperature read_vou t/read_iout (3 readings) read_temperature_1 mfr_vout_peak/mfr_iout_peak mfr_temperature_peak mfr_vout_min each fault is written into the next fault log each command read accesses the next fault log fault occurrence mfr _ nv_fault_ log fault log index 0 (255 bytes) fault log index 1 (255 bytes) fault log index 2 (255 bytes) fault log index 14 (255 bytes) flash max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 63 downloaded from: http:///
table 34. mfr_nv_fault_log (dch) byte parameter byte parameter 0 00h/fault_log_index 128 read_vout/read_iout t1 page 11 2 fault_log_count 130 read_vout/read_iout t2 page 11 4 mfr_time_count (lsw) 132 read_vout/read_iout t0 page 12 6 mfr_time_count (msw) 134 read_vout/read_iout t1 page 12 8 0000h 136 read_vout/read_iout t2 page 12 10 status_cml/00h 138 read_vout/read_iout t0 page 13 12 status_word 140 read_vout/read_iout t1 page 13 14 status_vout/status_iout pages 0/1 142 read_vout/read_iout t2 page 13 16 status_vout/status_iout pages 2/3 144 read_vout/read_iout t0 page 14 18 status_vout/status_iout pages 4/5 146 read_vout/read_iout t1 page 14 20 status_vout/status_iout pages 6/7 148 read_vout/read_iout t2 page 14 22 status_vout/status_iout pages 8/9 150 read_vout/read_iout t0 page 15 24 status_vout/status_iout pages 10/11 152 read_vout/read_iout t1 page 15 26 status_vout/status_iout pages 12/13 154 read_vout/read_iout t2 page 15 28 status_vout/status_iout pages 14/15 156 0000h 30 status_mfr_specific pages 0/1 158 0000h 32 status_mfr_specific pages 2/3 160 0000h 34 status_mfr_specific pages 4/5 162 0000h 36 status_mfr_specific pages 6/7 164 mfr_vout_peak/mfr_iout_peak page 0 38 status_mfr_specific pages 8/9 166 mfr_vout_peak/mfr_iout_peak page 1 40 status_mfr_specific pages 10/11 168 mfr_vout_peak/mfr_iout_peak page 2 42 status_mfr_specific pages 12/13 170 mfr_vout_peak/mfr_iout_peak page 3 44 status_mfr_specific pages 14/15 172 mfr_vout_peak/mfr_iout_peak page 4 46 status_mfr_specific page 255/00h 174 mfr_vout_peak/mfr_iout_peak page 5 48 status_temperature pages 16/17 176 mfr_vout_peak/mfr_iout_peak page 6 50 status_temperature pages 18/19 178 mfr_vout_peak/mfr_iout_peak page 7 52 status_temperature page 20/00h 180 mfr_vout_peak/mfr_iout_peak page 8 54 current_channels (note 1) 182 mfr_vout_peak/mfr_iout_peak page 9 56 0000h 184 mfr_vout_peak/mfr_iout_peak page 10 58 0000h 186 mfr_vout_peak/mfr_iout_peak page 11 60 read_vout/read_iout t0 page 0 (notes 2, 3) 188 mfr_vout_peak/mfr_iout_peak page 12 62 read_vout/read_iout t1 page 0 190 mfr_vout_peak/mfr_iout_peak page 13 64 read_vout/read_iout t2 page 0 192 mfr_vout_peak/mfr_iout_peak page 14 66 read_vout/read_iout t0 page 1 194 mfr_vout_peak/mfr_iout_peak page 15 68 read_vout/read_iout t1 page 1 196 mfr_vout_min page 0 70 read_vout/read_iout t2 page 1 198 mfr_vout_min page 1 72 read_vout/read_iout t0 page 2 200 mfr_vout_min page 2 74 read_vout/read_iout t1 page 2 202 mfr_vout_min page 3 76 read_vout/read_iout t2 page 2 204 mfr_vout_min page 4 78 read_vout/read_iout t0 page 3 206 mfr_vout_min page 5 80 read_vout/read_iout t1 page 3 208 mfr_vout_min page 6 82 read_vout/read_iout t2 page 3 210 mfr_vout_min page 7 84 read_vout/read_iout t0 page 4 212 mfr_vout_min page 8 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 64 downloaded from: http:///
note 1: current_channels is a bitmask (0 = voltage/1 = current) indicating which channels are enabled for c urrent measure - ment. note 2: for read_vout, read_iout, t2 is the oldest reading and t0 is the newest reading. note 3: status_v(i)out and read_v(i)out depend on whether the channel is configured to monitor voltage or c urrent. note 4: log_valid is set to ddh if the fault log contains valid data. mfr_time_count (ddh) the mfr_time_count command returns the current value of a real time counter which increments every 5ms, 20ms, 80ms, or 160ms depending on the configuration of the nv_log_depth bits in mfr_nv_log_config. this counter is useful in determining the time between multiple faults. the counter is a 32-bit value that rolls over. the count is reset to zero upon device power cycle or rst action or a soft reset. mfr_time_count can be preset to any value and starts counting up from the preset value. mfr_channel_config (e4h) the mfr_channel_config command is used to con - figure the monitoring channels (pages 0 to15). this com - mand should not be changed while the power supplies are operating. the mfr_channel_config command is described in table 35 and figure 12 . each rs/gpi pin can be independently configured using the select[5:0] bits to one of the following: monitor voltage; use the monitored voltage for sequencing (select[5:0] = 10h) monitor voltage; do not use for sequencing (select[5:0] = 20h) monitor current (select[5:0] = 22h) read voltage only; do not monitor for voltage faults or warnings (select[5:0] = 21h) read current only; do not monitor for current faults or warnings (select[5:0] = 23h) general-purpose input (gpi); active low (select[5:0] = 30h) general-purpose input (gpi); active high (select[5:0] = 34h) input is disabled (select[5:0] = 00h) table 34. mfr_nv_fault_log (dch) (continued) byte parameter byte parameter 86 read_vout/read_iout t1 page 4 214 mfr_vout_min page 9 88 read_vout/read_iout t2 page 4 216 mfr_vout_min page 10 90 read_vout/read_iout t0 page 5 218 mfr_vout_min page 11 92 read_vout/read_iout t1 page 5 220 mfr_vout_min page 12 94 read_vout/read_iout t2 page 5 222 mfr_vout_min page 13 96 read_vout/read_iout t0 page 6 224 mfr_vout_min page 14 98 read_vout/read_iout t1 page 6 226 mfr_vout_min page 15 100 read_vout/read_iout t2 page 6 228 0000h 102 read_vout/read_iout t0 page 7 230 0000h 104 read_vout/read_iout t1 page 7 232 read_temperature_1 page 16 106 read_vout/read_iout t2 page 7 234 read_temperature_1 page 17 108 read_vout/read_iout t0 page 8 236 read_temperature_1 page 18 110 read_vout/read_iout t1 page 8 238 read_temperature_1 page 19 112 read_vout/read_iout t2 page 8 240 read_temperature_1 page 20 114 read_vout/read_iout t0 page 9 242 mfr_temperature_peak page 16 116 read_vout/read_iout t1 page 9 244 mfr_temperature_peak page 17 118 read_vout/read_iout t2 page 9 246 mfr_temperature_peak page 18 120 read_vout/read_iout t0 page 10 248 mfr_temperature_peak page 19 122 read_vout/read_iout t1 page 10 250 mfr_temperature_peak page 20 124 read_vout/read_iout t2 page 10 252 0000h 126 read_vout/read_iout t0 page 11 254 log_valid (note 4) max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 65 downloaded from: http:///
* for proper sequencing, the select bits in mfr_psen_config must set to 000. if the monitoring channel is configured to monitor voltage for sequencing (select[5:0] = 10h), then the associated psen output channel must also be configured for control - ling power supplies by setting the select bits in mfr_ psen_config to 000. see the mfr_psen_config command description for more details. when the rs/gpi pins are configured as general-purpose inputs (gpi), the read_vout command reports 0000h when the pin is inactive and 0001h when the pin is active. also when the rs/gpi pins are configured to monitor voltage or act as gpi (select[5:0] = 10h or 20h or 30h or 34h), each channel can be independently configured to generate a signature signal at the seq output to facilitate event-based sequencing in multiple device sys - tems by indicating that this power supply has reached its power_good_on level and other channels can now proceed with their power-up. table 35. mfr_channel_config (e4h) bit name meaning 15:12 0 these bits always return a 0. 11:8 seq_generate these bits determine which seq signature the channel should generate after crossing the power_good_on level: 0000 disabled 1000 signature 8 0001 signature 1 1001 signature 9 0010 signature 2 1010 signature 10 0011 signature 3 1011 signature 11 0100 signature 4 1100 signature 12 0101 signature 5 1101 signature 13 0110 signature 6 1110 signature 14 0111 signature 7 1111 signature 15 7:6 0 these bits always return a 0. 5:0 select[5:0] these bits select the function of the rs/gpi pins: select[5:0] selected channel function 010000 (10h) sequencing + voltage monitoring* 100000 (20h) voltage monitoring (no sequencing) 100010 (22h) current monitoring 100001 (21h) voltage read only 100011 (23h) current read only 110000 (30h) general-purpose input active low 110100 (34h) general-purpose input active high 000000 (00h) disabled max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 66 downloaded from: http:///
figure 12. mfr_channel_config command pg0Cpg15 mfr_fault_response mfr_fault_response vout_scale_monitor power_good_on power_good_off logic level (active high/low) seq generate select or mfr_gpo_config read_vout gpi0Cgpi15 seq vout_ov_fault_limit vout_ov_warn_limit vout_uv_fault_limit vout_uv_warn_limit iout_cal_gain read_iout iout_oc_fault_limit iout_oc_warn_limit vout_scale_monitor read_vout iout_cal_gain read_iout read_vout mfr_channel_config note: signals listed in italics are internal signals that connect to other devi ce functions. shaded blocks are pmbus command seq gpo32 gpo32 16 voltage monitor select = 10h or 20h current monitor select = 22h voltage read-only select = 21h current read-only select = 23h general-purpose input select = 30h or 34h disabled select = 00h rs0Crs15 gpi0Cgpi15 0000h when inactive 0001h when active bits 11:8 bits 5:0 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 67 downloaded from: http:///
mfr_ton_seq_max (e6h) the mfr_ton_seq_max command sets an upper limit, in milliseconds, from a sequencing group (either sequence0 or sequence1 or sequence2 or sequence3 as chosen by the seq_select bits in the mfr_seq_config command) initiating the power-up sequence until the channel expects to begin its power-up based on an event which could be either a logic combi - nation of power-good (pg) and gpi signals or a match on the seq pin as configured with the select bits in mfr_seq_config. the 2 data bytes are in direct format. if this value is zero, then the limit is disabled. in response to the mfr_ton_seq_max being exceeded, the device does the following: 1) sets the vout bit in status_word. 2) sets the ton_max_fault bit in status_vout. 3) responds as specified in the mfr_fault_response. 4) notifies the host using alert assertion (if enabled in mfr_mode). mfr_seq_config (e8h) the mfr_seq_config command is used to configure the sequencing channels (pages 0 to15). this command should not be changed while the power supplies are oper - ating. the mfr_seq_config command is described in table 36 and figure 2 . each channel can be independently configured to initiate power-on sequencing using the select[1:0] bits to one of the following conditions: wait for either sequence0 or sequence1 or sequence2 or sequence3 from on_off_ config decode (select[1:0] = 00). wait for all enabled channel power-good (pg) or gpi are asserted (select[1:0] = 01). wait for a match on the seq pin (select[2:0] = 10). if select[1:0] = 00, the channel waits for either the sequence0 or sequence1 or sequence2 or sequence3 signal to assert before powering on. which sequence signal to use is selected with the seq_ select bits. the sequence (0 to 3) signals are generated by decoding the operation command and control0/1/2/3 pins using the on_off_config com - mand. see the on_off_config command description for details. this selection would be used if the channel is being controlled by time-based sequencing. if select[1:0] = 01, then sequencing for this channel is initiated when some combination of power-goods (pg) and general purpose inputs (gpi) are asserted. which channels should be used in this combination are selected using the pg_gpi_select bits (bit 16 to 31). if the pg_gpi_select bit is cleared, then the associated channel is not used in the logical combination to assert the gpo output. if the pg_gpi_select bit is set, then the power-good or gpi from this channel is used in the logical combination to initiate the power-on sequencing. this selection would be used if the channel is being con - trolled by event-based sequencing. if select[1:0] = 10, then sequencing is initiated when the channel matches the selected signature on the seq pin. use the the seq_match bits to select which sig - nature to match. the seq signal is used to facilitate event-based sequencing in multiple device systems. this selection would be used if the channel is being controlled by event-based sequencing. mfr_dac_config (e9h) the mfr_dac_config command is used to configure the individual dacx/gpoy (x = 0 to 11 / y = 16 to 27) outputs. this command should not be changed while the power supplies are operating. the mfr_dac_config command is described in table 37 and figure 13 . each dac/gpo pin can be independently configured using the select[2:0] bits to one of the following: dac margining operation (select[2:0] = 000) force pin assertion (select[2:0] = 001) force pin deassertion (select[2:0] = 010) assert when all enabled channel power-good (pg) or gpi are asserted (select[2:0] = 011) assert when any enabled alarm goes active (select[2:0] = 100) also each dac/gpo pin can be independently configured to be either active high or active low and either push-pull or open drain using the hi_lo and pp_od bits, respectively. if select[2:0] = 011, the dac/gpo output is configured to assert when some combination of power-goods (pg) and general purpose inputs (gpi) from each channel are asserted. which channels should be used in this combi - nation are selected using the pg_gpi_select bits (bit 16 to 31). if the pg_gpi_select bit is cleared, then the associated channel is not used in the logical combination to assert the gpo output. if the pg_gpi_select bit is set, then the power-good or gpi from this channel is used in the logical combination to assert the gpo output. this function is useful in creating system power-good signals. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 68 downloaded from: http:///
if select[2:0] = 100, the dac/gpo output is configured to assert when any of the enabled channel alarms goes active. the channel alarms are enabled with the alarm_ select bits (bit 16 to 31). if the alarm_select bit is cleared, then the alarm from this channel is blocked. if the alarm_select bit is set, then the alarm from this channel is routed to an or function such that any enabled alarm asserts the gpo output. the alarm function is cho - sen with the alarm_config bits in the mfr_fault_ response command. this function is useful in system debug or for enabling system status leds. table 36. mfr_seq_config (e8h) bit name meaning 31:16 pg_gpi_select these bits are only used if select[1:0] = 01; each bit corresponds to one channel (device channel n + 16 = bit number). when these bits are cleared, the power-good (pg) or gpi from channel n is not used in the logical and to initiate power-on sequencing. when these bits are set, the pg or gpi is used. 15:12 0 these bits always return a 0. 11:8 seq_match these bits determine which seq signature the channel must match before initiating power on sequencing: 0000 disabled 1000 signature 8 0001 signature 1 1001 signature 9 0010 signature 2 1010 signature 10 0011 signature 3 1011 signature 11 0100 signature 4 1100 signature 12 0101 signature 5 1101 signature 13 0110 signature 6 1110 signature 14 0111 signature 7 1111 signature 15 7:6 0 these bits always return a 0. 5:4 select[1:0] these bits determine the signal that initiates power-on sequencing: selected power-on select[1:0] sequencing control signal sequencing type 00 sequencen (n = 1, 2, 3) (use bits 1:0) time-based 01 pg/gpi logic combination (use bits 31:16) event-based 10 seq match (use bits 11:8) event-based 11 reserved 3:2 0 these bits always return a 0. 1:0 seq_select[1:0] 00 = sequence001 = sequence1 10 = sequence2 11 = sequence3 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 69 downloaded from: http:///
note 1: on_delay and off_delay are only available for the pg/gpi and alarm options. note 2: the actual time delays are 2ms to 3ms longer than configured due to processing delays within the device. table 37. mfr_dac_config (e9h) bit name meaning 31:16 pg_gpi_select alarm_select these bits are only used if select[2:0] = 011 or 100; each bit corresponds to one channel (device channel n + 16 = bit number): select[2:0] bit function 011 when this bit is cleared, the power-good (pg) or gpi from channel n is not used in the logical and to assert the gpo output. when this bit is set, the pg or gpi is used. 100 when this bit is cleared, the alarm from channel n is blocked from the logical or to assert the gpo output. when this bit is set, the alarm signal is routed to the logical or. 15:12 off_delay these bits determine the delay time to pin deassertion (notes 1 and 2): off_delay[3:0] delay time off_delay[3:0] delay time 0000 0ms 1000 200ms 0001 5ms 1001 400ms 0010 10ms 1010 600ms 0011 20ms 1011 800ms 0100 40ms 1100 1000ms 0101 60ms 1101 1500ms 0110 80ms 11 10 2000ms 0111 100ms 11 11 4000ms 11:8 on_delay these bits determine the delay time to pin assertion (notes 1 and 2): on_delay[3:0] delay time on_delay[3:0] delay time 0000 0ms 1000 200ms 0001 5ms 1001 400ms 0010 10ms 1010 600ms 0011 20ms 1011 800ms 0100 40ms 1100 1000ms 0101 60ms 1101 1500ms 0110 80ms 11 10 2000ms 0111 100ms 11 11 4000ms 7 pp_od 0 = dac/gpo push-pull output 1 = dac/gpo open-drain output 6 hi_lo 0 = dac/gpo active low1 = dac/gpo active high 5:3 0 these bits always return a 0. 2:0 select[2:0] these bits determine the function selected on the pin: select[2:0] gpo pin selected function 000 dac operation 001 force gpo assertion 010 force gpo deassertion 011 pg/gpi operation (use bits 31:16) 100 alarm operation (use bits 31:16) 101 reserved 110 reserved 111 reserved max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 70 downloaded from: http:///
delay function if a delay is configured (either on or off), the input must be continuously static through the delay time before the output changes state (see figure 9 ). mfr_margin_config (dfh) the mfr_margin_config command configures the internal voltage dacs to margin the associated power supplies. if the dac pin is configured with the mfr_ dac_config for any function besides dac opera - tion, this selection overrides the margining functionality. the mfr_margin_config command is described in table 38 . power-supply margining operation for the power supplies connected to psen0 to psen15 (pages 0 to 15), power-supply margining is implemented using the dac0 to dac15 outputs, respectively. the device close-loop controls the dac output voltage to margin the power supply. when margining is not active, the dac outputs are high impedance unless the vout_ command is active. table 38. mfr_margin_config (dfh) figure 13. mfr_dac_config functional logic bit name meaning 15 slope dac setting to resulting voltage relationship: 0 = negative slope (higher dac voltage results in a lower power-supply voltage) 1 = positive slope (higher dac voltage results in a higher power-supply voltage) 14 open_loop 0 = normal closed-loop margining 1 = dac value set constantly to the dc_dac value when margining invoked 13:8 0 these bits always return a 0. 7:0 dac this 8-bit value has two purposes. 1) used as the initial dac voltage when the device begins to margin a power supply either up or down. 2) when bit 14 is set, this value is used to set the dac level. force gpo assertion force gpo deassertion on_delay off_delay or or and 16 12 16 16 16 16 select 001 010 100 011 note: signals listed in italics are internal signals that connect to other devi ce functions. shaded blocks are pmbus commands. select alarm0 C alarm15 and and pg 0/ gpi0 C pg1 5 /gpi15 bits 31:16 bits 2:0 dac 000 bit 6 bits 15:8 bit 7 mfr_dac_config not available for force gpo assertion or deassertion active high/low open drai n/ push-pull dacx/gpoy (x = 0C 11) (y = 18C 27) dacx (x = 0C 11) max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 71 downloaded from: http:///
the device margins the power supplies when operation is set to one of the margin states. margining of the sup - plies does not begin until all power supplies have exceed - ed their programmed power_good_on levels. when this happens, the dac output is enabled and margining is initiated. the device then averages four samples of vout for a total time of 20ms. if the measured vout and the target (set by either vout_margin_high or vout_margin_low) differ by more than 1%, the dac setting is adjusted by one step. the direction of the duty cycle adjustment is determined by the slope bit in mfr_margin_config. all changes to the dac set - ting are made after averaging 4 samples of vout over a 20ms period. when the operation command deactivates margining and the margining has been running with the ignore all faults condition, then the device does not begin monitoring for faults for 100ms after the margin off input is received to allow time for the power supplies to return to a normal condition. margining faults the device detects two possible margining faults. first, if the initial dac step causes vout to exceed the target value (either high or low depending on whether the device has been instructed to margin high or low respectively), this creates a fault. second, if the target value cannot be reached when the dac reaches zero or full scale, this also creates a fault. if either margining fault occurs, the device continues attempting to margin the power supply and does the following: 1) sets the margin bit in status_word. 2) sets the margin_fault bit in status_mfr_ specific (pages 0 to 15). 3) notifies the host through alert assertion (if enabled in mfr_mode). dac value the dac value can be determined by the following formula. dac value = 256 x (v fb /2.048) where v fb = power-supply feedback node voltage. example: v fb = 0.8v dac value = 256 x (0.8/2.048) = 100d = 0x64h dac margining component selection the external components needed to realize the margin - ing circuitry for the voltage dac outputs are shown in figure 14 and described in the formulas below. dac r = (v fb C 0.1)/(i fb x margining range x 120%) where v fb = feedback node voltage and i fb = feedback node current.example: v fb = 0.8v, i fb = 10a, margining range = 10% dac r value = (0.8 C 0.1)/(10a x 10% x 120%) = 583k? temperature sensor operation the device can monitor up to five different temperature sensorsfour external sensors plus its own internal tem - perature sensor. the external temperature sensors are all connected in parallel to the master i 2 c port (msda and mscl pins). the device can support up to four ds75lv devices. each of the enabled temperature sensors are measured once a second. the internal temperature sensor is aver - aged four times to reduce the affect of noise. each time the device attempts to read a temperature sensor, it checks for faults. for the internal temperature sensor, a fault is defined as reading greater than +130 c or less than -60 c. for the i 2 c temperature sensors, a fault is defined as a communication access failure. temperature sensor faults are reported by setting the temperature reading to 7fffh. a temperature sensor fault results in the setting of the temperature bit in status_word and alert is asserted (if enabled in mfr_mode). no bits are set in status_temperature. on device reset, if the device cannot initialize the external ds75lv device, the temperature bit in status_word is set and alert is asserted (if enabled in mfr_mode), but the device does not attempt to reinitialize the ds75lv until 8000h is written to mfr_temp_sensor_config. reading disabled temperature sensors returns a fixed value of 0000h. figure 14. margining hardware configurations i fb v fb r v out dac power supply max34462 fb/trim max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 72 downloaded from: http:///
up to four ds75lv digital temperature sensors can be controlled by the max34462. the a0/1/2 pins on the ds75lv should be configured as shown in table 39 . the thermostat function on the ds75lv is not used, therefore the o.s. output should be left open circuit. mfr_temp_sensor_config (f0h) the mfr_temp_sensor_config command is used to configure the temperature sensors. the mfr_temp_ sensor_config command is described in table 40 . mfr_gpo_config (f8h) the mfr_gpo_config command is used to configure the individual gpo28 to gpo34 pins. there is a separate pmbus page for each gpo output. see table 41 for details. some of these pins share functions with alternate functions such as fault outputs and the seq output. this command should not be changed while the power supplies are operating. the mfr_gpo_config com - mand is described in the table 42 and figure 15 . each gpo pin can be independently configured using the select[2:0] bits to one of the following: non-gpo function (see table 41 ) (select[2:0] = 000) force pin assertion (select[2:0] = 001) force pin deassertion (select[2:0] = 010) assert when all enabled channel power-good (pg) or gpi are asserted (select[2:0] = 011) assert when any enabled alarm goes active (select[2:0] = 100) also each gpo pin can be independently configured to be either active high or active low and either push-pull or open drain using the hi_lo and pp_od bits, respectively. if select[2:0] = 011, the gpo output is configured to assert when some combination of power-goods (pg) and general purpose inputs (gpi) from each channel are asserted. which channels should be used in this combi - nation are selected using the pg_gpi_select bits (bit 16 to 31). if the pg_gpi_select bit is cleared, then the associated channel is not used in the logical combination to assert the gpo output. if the pg_gpi_select bit is set, then the power-good or gpi from this channel is used in the logical combination to assert the gpo output. this function is useful in creating system power-good signals. if select[2:0] = 100, the gpo output is configured to assert when any of the enabled channel alarms goes active. the channel alarms are enabled with the alarm_ select bits (bit 16 to 31). if the alarm_select bit is cleared, then the alarm from this channel is blocked. if the alarm_select bit is set, then the alarm from this channel is routed to an or function such that any enabled alarm asserts the gpo output. the alarm function is cho - sen with the alarm_config bits in the mfr_fault_ response command. this function is useful in system debug or for enabling system status leds. table 39. ds75lv address pin configuration table 40. mfr_temp_sensor_config (f0h) table 41. gpo description page max34462 temp sensor ds75lv address pin configuration a2 a1 a0 16 max34462 internal 17 ds75lv (address 90h) 0 0 0 18 ds75lv (address 92h) 0 0 1 19 ds75lv (address 94h) 0 1 0 20 ds75lv (address 96h) 0 1 1 bit name meaning 15 enable 0 = temperature sensor disabled 1 = temperature sensor enabled 14:0 0 these bits always return a 0. name ball pmbus page non-gpo pin function when select[2:0] = 000 gpo28 j9 21 fault0 gpo29 k10 22 fault1 gpo30 j10 23 fault2 gpo31 h9 24 fault3 gpo32 d7 25 seq gpo33 e5 26 high impedance gpo34 e10 27 high impedance gpo35 d10 28 sync max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 73 downloaded from: http:///
note 1: on_delay and off_delay are only available for pg/gpi and alarm. note 2: the actual time delays are 2ms to 3ms longer than configured due to processing delays within the device. table 42. mfr_gpo_config (f8h) bit name meaning 31:16 pg_gpi_select alarm_select these bits are only used if select[2:0] = 011 or 100; each bit corresponds to one channel (device channel n + 16 = bit number): select[2:0] bit function 011 when this bit is cleared, the power-good (pg) or gpi from channel n is not used in the logical and to assert the gpo output. when this bit is set, the pg or gpi is used. 100 when this bit is cleared, the alarm from channel n is blocked from the logical or to assert the gpo output. when this bit is set, the alarm signal is routed to the logical or. 15:12 off_delay these bits determine the delay time to pin deassertion (notes 1 and 2): off_delay[3:0] delay time off_delay[3:0] delay time 0000 0ms 1000 200ms 0001 5ms 1001 400ms 0010 10ms 1010 600ms 0011 20ms 1011 800ms 0100 40ms 1100 1000ms 0101 60ms 1101 1500ms 0110 80ms 11 10 2000ms 0111 100ms 11 11 4000ms 11:8 on_delay these bits determine the delay time to pin assertion (notes 1 and 2): on_delay[3:0] delay time on_delay[3:0] delay time 0000 0ms 1000 200ms 0001 5ms 1001 400ms 0010 10ms 1010 600ms 0011 20ms 1011 800ms 0100 40ms 1100 1000ms 0101 60ms 1101 1500ms 0110 80ms 11 10 2000ms 0111 100ms 11 11 4000ms 7 pp_od 0 = gpo push-pull output 1 = gpo open-drain output 6 hi_lo 0 = gpo active low1 = gpo active high 5:3 0 these bits always return a 0. 2:0 select[2:0] these bits determine the function selected on the pin: select[2:0] gpo pin selected function 000 non-gpo operation 001 force gpo assertion 010 force gpo deassertion 011 pg/gpi operation (use bits 31:16) 100 alarm operation (use bits 31:16) 101 reserved 110 reserved 111 reserved max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 74 downloaded from: http:///
delay function if a delay is configured (either on or off), the input must be continuously static through the delay time before the output changes state. see figure 9 . applications information dvdd, avdd, vref, and reg18 decoupling to achieve the best results when using the device, decouple each dvdd and avdd power input with a 0.1f capacitor. all dvdd and avdd pins should be connected together. all dvss and avss pins should be connected together. use high-quality, ceramic, surface-mount capac - itors. surface-mount components minimize lead induc - tance, which improves performance, and ceramic capaci - tors tend to have adequate high-frequency response for decoupling applications. decouple the reg18 regulator output using 1f (maximum esr of 500m?) and 10nf capacitors and decouple reg18a with a 0.1f capacitor. decouple the vref output using a 22nf capacitor. open-drain pins msda, mscl, scl, sda, fault , seq , psen, and alert are open-drain pins and require external pullup resistors connected to dvdd to realize high logic levels. keep-alive circuit in systems where the power to the max34462 may be not always be present, a keep-alive circuit consisting of a schottky diode and a bulk capacitor can be added to allow the device time to orderly shutdown the power supplies it is controlling before power is lost. coniguration port some applications may require the ability to configure the max34462 when the device has been mounted on a pcb. in such applications, a 3- or 4-wire header can be added to allow access to the slave i 2 c pins. resistor-dividers and source impedance for rs inputs the maximum full-scale voltage on the adc inputs is 2.048v (nominal). a resistor-divider must be used to mea - sure voltages greater than 1.8v. the maximum source impedance to the rs inputs when voltage is measured is determined by the adc_time bits in mfr_mode. see the recommended operating conditions section for more details.protecting input pins in applications where voltages can be applied to the rs/ gpi, sync, or control signals when v dd or v dda is grounded or open, a series 100? resistor is recommend - ed to protect the device by limiting power dissipation. figure 15. mfr_gpo_config functional logic force gpo assertion force gpo deassertion ton_delay toff_delay or or and 16 8 16 16 16 16 select 001 010 100 011 note: signals listed in italics are internal signals that connect to other devi ce functions. shaded blocks are pmbus commands. select alarm0 C alarm15 and and pg 0/ gpi0 C pg1 5 /gpi15 bits 31:16 bits 2:0 bit 6 bit 15:8 bit 7 mfr_gpo_config not available for force gpo assertion or deassertion active high/low open drai n/ push-pull fault0 gpo28 (page 21) fault1 gpo29 (page 22) fault2 gpo30 (page 23) fault3 gpo31 (page 24) seq gpo32 (page 25) hi-z gpo33(page 26) hi-z gpo34(page 27) sync gpo35 (page 28) non-gpo 000 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 75 downloaded from: http:///
typical operating circuit max34462 msdamscl psen0C psen15 avddavss dvdd ds75lv i 2 c temp sensor (i 2 c addresses 90/92/94/96h) optional keep alive optional configuration access optional remote temp sensors (up to 4) sdascl alert addr 3.3v rst fault0/1/2/3control0/1/2/3 reg18 reg18a host interface power control dac0Cdac15 sync vref 20khz sequencingsynchronization clock only required if the monitored voltage is > 1.8v power supply current- sense amplifier optional current monitoring load in out trim en rsp0Crsp15 rsn0Crsn15 dvss max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 76 downloaded from: http:///
+denotes a lead(pb)-free/rohs-compliant package. t = tape and reel. part temp range pin-package MAX34462EXQ+ -40c to +95c 100 csbga MAX34462EXQ+t -40c to +95c 100 csbga package type package code outline no. land pattern no. 100 csbga x10011+1 21-0352 90-0292 max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs www.maximintegrated.com maxim integrated 77 package information for the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages . note that a +, #, or - in the package code indicates rohs status only. package drawings may show a different suffix character, but the drawing pertains to the package regardless of rohs status. ordering information downloaded from: http:///
revision number revision date description pages changed 0 9/13 initial release maxim integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a maxim integrated product. no circuit patent licenses are implied. maxim integrated reserves the right to change the circuitry and speciications without n otice at any time. the parametric values (min and max limits) shown in the electrical characteristics table are guaranteed. other parametric values quoted in this data sheet are provided for guidance. maxim integrated and the maxim integrated logo are trademarks of maxim integrated products, inc. max34462 pmbus 16-channel monitor/sequencer with differential inputs and margining dacs ? 2013 maxim integrated products, inc. 78 revision history for pricing, delivery, and ordering information, please contact maxim direct at 1-888-629-4642, or visit maxim integrateds website at www.maximintegrated.com. downloaded from: http:///

▲Up To Search▲

Price & Availability of MAX34462EXQ

	To Download MAX34462EXQ Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .