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data sheet rev. 1.11 / june 2011 ZSSC3008 sensor signal conditioner with diagnostics
ZSSC3008 sensor signal conditioner with diagnostics ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. brief description the ZSSC3008 is a sensor signal conditioner ic that is adjustable to nearly all piezo-resistive bridge sen- sors. measured and corrected bridge values are pro- vided at the sig? pin, which can be configured as an analog voltage output or as a one-wire serial dig- ital output. the digital one-wire interface (owi) can be used for a simple pc-controlled calibration procedure to pro- gram a set of calibration coefficients into an on-chip eeprom. the calibrated ZSSC3008 and a specific sensor are mated digitally: fast, precise, and without the cost overhead associated with trimming by exter- nal devices or laser. integrated diagnostics functions make the ZSSC3008 particularly well-suited for auto- motive applications.* features ? digital compensation of sensor offset, sensitivity, and non-linearity ? programmable analog gain and digital gain; accommodates bridges with spans < 1mv/v and high offset ? many diagnostic features on chip (e.g., eeprom signature, bridge connection checks, bridge short detection, power loss detection) zssc300 p 8 sig? vb vbn vss vgate 0.1 ? f v s .7 upply ground +2 5 v to +5. out/owi vdd ? independently programmable high and low clipping levels ? 24-bit customer id field for module traceability ? output options: rail-to-rail ratiometric analog voltage (12-bit resolution), absolute analog voltage, digital one-wire interface ? fast power-up to data out response; output available 5ms after power-up ? current consumption depends on programmed sample rate: 1ma down to 250 ? a (typical) ? fast response time: 1ms (typical) ? high voltage protection up to 30v with external jfet benefits ? pc-controlled configuration and calibration via one-wire interface ? simple, low cost ? high accuracy (0.1% fso @ -25 to 85c; 0.25% fso @ -40 to 125c) ? single-pass calibration ? quick and precise available support ? development kit available ? multi-unit calibrator kit available ? support for industrial mass calibration available ? quick circuit customization possible for large production volumes physical characteristics ? wide operation temperature: ?40c to +125c ? supply voltage 2.7 to 5.5v; with external jfet, 5.5 to 30v ? small sop8 package ZSSC3008 application circuit * not aec-q100-qualified.
ZSSC3008 sensor signal conditioner with diagnostics ? 2011 zentrum mikroelektronik dresden ag ? rev.1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. ZSSC3008 block diagram analog block digital block ZSSC3008 0.1 f vss vbp 12-bit dac outbuf1 zacwire tm interface digital core eeprom with charge pump preamp inmux vdd regulator power save por/oscillator vbn vgate sig tm bsink (optional) v dd (2.7 to 5.5 v) jfet 1 (optional if s u s pply is 2.7 to 5.5 v) d v supply 5.5 v to 30 v sensor diagnostics power lost diagnostic a d 14-bit adc _ + 0 v to 1 v ratiometric rail-to-rail owi/zacwire tm highly versatile applications in many markets including ? industrial ? building automation ? office automation ? white goods ? automotive * ? portable devices ? your innovative designs * not aec-q100-qualified. rail-to-rail ratiometric voltage output applications absolute analog voltage output applications product ordering codes (please contact zmdi sales for additional options.) sales code description package ZSSC3008aa2r ZSSC3008 sop8 (150 mil) ? temperature range: -40c to +125c tape and reel ZSSC3008aa2t ZSSC3008 sop8 (150 mil) ? temperat ure range: -40c to +125c tube ZSSC3008kit ZSSC3008 ssc evaluation kit: comm unication board, ssc board, sensor replacement board, evaluation software, usb cable, 5 ic samples kit sales and further information www.zmdi.com ssc@zmdi.com zentrum mikroelektronik dresden ag (zmd ag) grenzstrasse 28 01109 dresden germany zmd america, inc. 8413 excelsior drive suite 200 madison, wi 53717 usa zentrum mikroelektronik dresden ag, japan office 2nd floor, shinbashi tokyu bldg. 4-21-3, shinbashi, minato-ku tokyo, 105-0004 japan zmd far east, ltd. 3f, no. 51, sec. 2, keelung road 11052 taipei taiwan phone +49 (0)351.8822.7.772 fax +49(0)351.8822.87.772 phone +1 (608) 829-1987 fax +1 (631) 549-2882 phone +81.3.6895.7410 fax +81.3.6895.7301 phone +886.2.2377.8189 fax +886.2.2377.8199 disclaimer : this information applies to a product under development. its characteristics and specifications are subject to change without notice. zentrum mikroelektronik dresden ag (zmd ag) assumes no obligation regarding future manufacture unless otherwise agreed to in writing. the information furnished hereby is believed to be true and accurate. however, under no circumstances shall zmd ag be liable to any customer, licensee, or any other third party for any special, indirect, incident al, or consequential damages of any kind or nature whatsoever arising out of or in any way related to the furnishing, performance, or use of this technical data. zmd ag hereby expressly dis claims any liability of zmd ag to any customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of zmd ag for any dama ges in connection with or arising out of the furnishing, perfor- mance or use of this technical data, whether based on contract, warranty, tort (including negligence), strict liability, or oth erwise.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 4 of 46 contents 1 electrical char acterist ics ..................................................................................................... .8 1.1. absolute maxi mum rati ngs ............................................................................................8 1.2. recommended operati ng condit ions .............................................................................8 1.3. electrical pa rameters ......................................................................................................9 1.4. analog input versus ou tput reso lution ......................................................................... 11 2 circuit desc ription ............................................................................................................ ..14 2.1. signal flow and block diagram ....................................................................................14 2.2. analog front end ..........................................................................................................15 2.2.1. bridge supply ..........................................................................................................15 2.2.2. preamp bl ock ........................................................................................................15 2.2.3. analog-to-digital converter (adc)........................................................................... 15 2.3. digital signal processor ................................................................................................16 2.3.1. eeprom ................................................................................................................. 16 2.3.2. one-wire interfac e - zacw ire? ..............................................................................17 2.4. output st a ge.................................................................................................................17 2.4.1. digital to analog converte r (outp ut dac) with progra mmable clipping limits .......17 2.4.2. output bu ffer ........................................................................................................... 18 2.4.3. voltage referenc e block .........................................................................................18 2.5. clock generator / power-o n reset (c lkpor) ............................................................ 19 2.5.1. trimming the o scillat o r............................................................................................20 2.6. diagnostic features ...................................................................................................... 20 2.6.1. eeprom int egrity ...................................................................................................21 2.6.2. sensor connecti on chec k .......................................................................................21 2.6.3. sensor shor t check .................................................................................................21 2.6.4. power loss de tection ..............................................................................................22 3 functional de scripti on ........................................................................................................2 2 3.1. general work ing m ode .................................................................................................22 3.2. zacwire? communica tion interf ace ............................................................................24 3.2.1. properties and parameters ......................................................................................24 3.2.2. bit enc oding ............................................................................................................24
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 5 of 46 3.2.3. write operation from ma ster to z ssc3008 .............................................................25 3.2.4. ZSSC3008 read operati ons ...................................................................................25 3.2.5. high level pr otocol ..................................................................................................28 3.3. command/data byte s encodi ng ...................................................................................29 3.4. calibration sequence ....................................................................................................30 3.5. eeprom bi ts ...............................................................................................................32 3.6. calibrati on math ............................................................................................................ 35 3.6.1. correction coe fficients ............................................................................................35 3.6.2. interpretati on of binary numbers for correction c oefficient s...................................35 3.7. reading eeprom contents .........................................................................................37 4 application circu it ex am ples ..............................................................................................38 4.1. three-wire rail-to-rail ratiometric output ................................................................... 38 4.2. absolute analog vo ltage ou tput ...................................................................................39 4.3. three-wire ratiometric output with over-voltage protecti on .......................................40 4.4. digital ou tput ................................................................................................................4 0 4.5. output resistor/c apacitor li mits ..................................................................................40 5 eeprom restor ation ......................................................................................................... 41 5.1. default eeprom contents ...........................................................................................41 5.1.1. osc_tr im .................................................................................................................41 5.1.2. 1v_trim/jfet _trim ................................................................................................41 5.2. eeprom restoratio n procedure ..................................................................................41 6 pin configurati on and pa ckage ..........................................................................................43 7 esd/latch-up-pr otection ...................................................................................................44 8 test ........................................................................................................................... .........44 9 quality and reliability ........................................................................................................ .44 10 customiz ation .................................................................................................................. ...44 11 product orderi ng code s .....................................................................................................44 12 related docu ments ............................................................................................................45 13 definitions of acrony m s ......................................................................................................45 14 document revisi on history ................................................................................................46
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 6 of 46 list of figures figure 2.1 ZSSC3008 bloc k diagram......................................................................................................... ..........14 figure 2.2 dac output timing for highest update rate...................................................................................... 17 figure 3.1 general work ing mode........................................................................................................... .............23 figure 3.2 manchester du ty cycle.......................................................................................................... ..............24 figure 3.3 19-bit write fram e............................................................................................................. ..................25 figure 3.4 read acknowledge............................................................................................................... ...............25 figure 3.5 digital output (nom ) bridge readings ........................................................................................... ....26 figure 3.6 read eeprom contents ........................................................................................................... .........26 figure 3.7 transmission of a numb er of data packets ....................................................................................... .27 figure 3.8 zacwire? output timing for lower update rates.............................................................................28 figure 4.1 rail-to-rail ratiomet ric voltage output........................................................................................ .......38 figure 4.2 absolute analog voltage output with external jfet regulation........................................................39 figure 4.3 ratiometri c output............................................................................................................. ..................40 figure 5.1 eeprom validation and rest oration proc edure ................................................................................42 figure 6.1 ZSSC3008 pin-ou t diagram ....................................................................................................... ........43 list of tables table 1.1 absolute maxi mum rati ngs ...................................................................................................................8 table 1.2 recommended operat ing conditions ............................................................................................... ....8 table 1.3 supply/regulation ch aracteristics.............................................................................................. ...........9 table 1.4 parameters for analog front-e nd (afe) .......................................................................................... .....9 table 1.5 parameters for eepr om .......................................................................................................... ............9 table 1.6 parameters for a/d converter ................................................................................................... ............9 table 1.7 parameters for analog ou tput (dac and buffer) ................................................................................10 table 1.8 diagnostics .................................................................................................................... ......................10 table 1.9 parameters for zacwire? serial interface ....................................................................................... ..10 table 1.10 parameters for system response................................................................................................. ......11 table 1.11 adc resolution charac teristics for an anal og gain of 6 ....................................................................12 table 1.12 adc resolution charac teristics for an anal og gain of 24 ..................................................................12 table 1.13 adc resolution charac teristics for an anal og gain of 48 ..................................................................13 table 1.14 adc resolution charac teristics for an anal og gain of 96 ..................................................................13 table 2.1 1v reference trim (1v vs. trim for nominal process run)................................................................19 table 2.2 oscillator trimming............................................................................................................ ..................20 table 2.3 summary of diagno stic features ................................................................................................. .......21 table 3.1 pin configuration and latch-up co nditions ...................................................................................... ..24 table 3.2 special measurement/idle time betwe en packets versus update rate ............................................27 table 3.3 total transmission time for different update rate settings ..............................................................27 table 3.4 command/data by tes enc oding.................................................................................................... ......29 table 3.5 ZSSC3008 eepr om bits........................................................................................................... .........32
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 7 of 46 table 3.6 correction c oeffici ents ........................................................................................................ ................35 table 3.7 gain_b [13:0] weight ings ....................................................................................................... .............36 table 3.8 offset_b weightings ............................................................................................................ ................36 table 3.9 eeprom read order .............................................................................................................. ...........37 table 6.1 storage and solder ing conditions ............................................................................................... ........43 table 6.2 ZSSC3008 pin c onfiguration..................................................................................................... ..........43
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 8 of 46 1 electrical characteristics 1.1. absolute maximum ratings table 1.1 absolute maximum ratings parameter symbol min. max. unit analog supply voltage v dd -0.3 6.0 v voltages at analog i/o ? in pin v ina -0.3 vdd+0.3 v voltages at analog i/o ? out pin v outa -0.3 vdd+0.3 v storage temperature range ( ? 10 hours) t stor -50 150 c storage temperature range (<10 hours) t stor <10h -50 170 c note: also see table 6.1 regarding soldering temperature and storage co nditions for the sop-8 package. 1.2. recommended operating conditions table 1.2 recommended operating conditions parameter symbol min. typ. max. unit analog supply voltage to ground v dd 2.7 5.0 5.5 v analog supply voltage (with external jfet regulator) v supp 5.5 7 30 v common mode voltage v cm 1 v dda - 1.3 v ambient temperature range 1, 2 t amb -40 125 ?c external capacitance between v dd and ground c vdd 100 220 470 nf output load resistance to v ss or v dd 3 r l,out 5 k? output load capacitance 4 c l,out 10 15 nf bridge resistance 5 r br 1 100 k? power-on rise time t pon 100 ms 1) note that the maximum eeprom programming temperature is 85c. 2) if buying die, designers should use cauti on not to exceed maximum junction temper ature by proper package selection. 3) only needed for analog output mode; not needed for digital output mode. when a pull-down resistor is used as load resistor, the power loss detection diagnostic for loss of vss cannot be assured at rl=5k; rl=10k is recommended for this configuration. 4) using the output for digital calibration, c l,out is limited by the maximum rise time t zacrise . see section 1.3. 5) note: minimum bridge resistance is only a fa ctor if using the bsink feature. the r ds (on) of the bsink transistor is 8 to 10 ? when operating at vdd=5v. this does give rise to a ratiometricity inaccuracy that bec omes greater with low bridge resistances.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 9 of 46 1.3. electrical parameters note: in this section, an asterisk (*) marks parameters for which there is no verification in mass production; the parameter is guaranteed by design and/or quality observation. table 1.3 supply/regulation characteristics parameter symbol min. typ. max. unit conditions supply voltage v dd 2.7 5.0 5.5 v 0.25 ma at minimum update rate supply current (varies with update rate and output mode) i dd 1.0 1.4 ma at maximum update rate power supply rejection ratio * psrr 60 db power-on reset level por 1.4 2.6 v table 1.4 parameters for analog front-end (afe) parameter symbol min. typ. max. unit conditions leakage current pin vbp,vbn i in_leak ? 10 na sensor connection and short check must be disabled. table 1.5 parameters for eeprom parameter symbol min. typ. max. unit conditions number write cycles n wri_eep 100k cycles at 85 ?c data retention t wri_eep 10 years at 100 ?c table 1.6 parameters for a/d converter parameter symbol min. typ. max. unit conditions adc resolution r adc 14 bit integral nonlinearity (inl) 1 inl adc -4 +4 lsb based on ideal slope differential nonlinearity (dnl) * dnl adc -1 +1 lsb 1) note: this is ? 4 lsbs for the 14-bit a-to-d conversion. this results in absolute accuracy to 12-bits on the a-to-d result. non-linearity is typically better at temperatures less than 125c.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 10 of 46 table 1.7 parameters for analog output (dac and buffer) parameter symbol min. typ. max. unit conditions max. output current i out 2.2 ma max. current maintaining accuracy resolution res 12 bit referenced to v dd 0.25 % v dd dac input to output ratiometric mode absolute error e abs 5 mv dac input to output 0-1v mode differential nonlinearity * dnl -0.9 +3.0 lsb 12bit no missing codes upper output voltage limit v out 95% v dd r l = 5 k ? lower output voltage limit v out 16.5mv mv with 5k? pull down, 0-1v output output short circuit protection limit i sc 3 40 ma depends on operating conditions. short circuit protection must be enabled via diag_cfg (eeprom word [102:100]). see section 2.4.2 . analog output noise peak-to-peak v noise,pp 5 1lsb mv shorted input table 1.8 diagnostics parameter symbol min. typ. max. unit conditions upper diagnostic output level v dia,h 97.5% v dd ratiometric analog output mode lower diagnostic output level v dia,l 2.5% v dd ratiometric analog output mode min. load resistor for power loss r l,out_ps 5 k? pull-up or pull-down 1 in analog output mode 1) when using a pull-down resistor as load resistor, the power loss detection diagnostic for loss of vss cannot be assured at rl=5 k; rl=10k is recommended for this configuration. table 1.9 parameters for zacwire? serial interface parameter symbol min. typ. max. unit conditions zacwire ? line resistance * r zac,load 3.9 k? zacwire ? load capacitance * c zac,load 0 1 15 nf the rise time must be t zac,rise = 2 ? r zac,load ? c zacload ? 5s . if using a pull-up resistor instead of a line resistor, it must meet this specification. the absolute maximum for c zacload is 15nf. voltage level low * v zac,low 0 0.2 v dd voltage level high * v zac,low 0.8 1 v dd
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 11 of 46 table 1.10 parameters for system response parameter symbol min. typ. max. unit conditions start-up-time t sta 5 ms power-up to output update_rate = 1 khz (1 ms) response time ? analog output t resp-a 1 2 ms update_rate = 1 khz (1 ms) response and transmission time for digital output t res, dig 1.6 ms varies with update rate. value given at fastest rate. sampling rate f s 1000 hz update_rate = 1 khz (1 ms) overall linearity error? digital e lind 0.025 0.04 % bridge input to output overall linearity error ? analog e lina 0.1 0.25 % bridge input to output overall ratiometricity error re out 0.035 % 10%vdd, not using bsink feature ? 0.1% -25c to 85c overall accuracy ? digital (only ic, without sensor bridge) ac outd ? 0.25% %fso -40c to 125c ? 0.35% %fso -25c to 85c overall accuracy ? analog 1) 2) (only ic, without sensor bridge) ac outa ? 0.5% %fso -40c to 125c 1) not included is the quantization noise of the dac. the 12-bit dac has a quantization noise of ? ? lsb = 0.61mv ( @ 5v vdd) = 0.0125%. 2) analog output range 2.5% to 95% 1.4. analog input versus output resolution the ZSSC3008 has a fully differential chopper-stabilized pr e-amplifier with 4 programmable gain settings. the output of the pre-amplifier feeds into a 14-bit charge-balanced adc. span, offset, and non-linearity correction are performed in the digital domain. then the resulting corrected bridge value can be output in analog form through a 12-bit dac or as a 16-bit serial digital packet. the reso lution of the output depends on the input span (bridge sensitivity) and the analog gain setting programmed. digital gai ns can vary from [0,32). analog gains available are 6, 24, 48, and 96. note: at higher analog gain settings, there will be higher output resolution, but the ability of the ZSSC3008 to handle large offsets decreases. this is expected because t he offset is also amplified by the analog gain and can therefore saturate the adc input.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 12 of 46 the following tables outline the guaranteed minimum re solution for a given bridge sensitivity range. table 1.11 adc resolution characte ristics for an analog gain of 6 analog gain 6 input span [mv/v] min. typ. max. allowed offset (+/- % of span) minimum guaranteed resolution [bits] 57.8 80.0 105.8 38% 12.4 50.6 70.0 92.6 53% 12.2 43.4 60.0 79.4 73% 12.0 36.1 50.0 66.1 101% 11.7 28.9 40.0 52.9 142% 11.4 21.7 30.0 39.7 212% 11.4 table 1.12 adc resolution characte ristics for an analog gain of 24 analog gain 24 input span [mv/v] min. typ. max. allowed offset (+/- % of span) minimum guaranteed resolution [bits] 18.1 25.0 33.1 17% 12.7 14.5 20.0 26.5 38% 12.4 7.2 10.0 13.2 142% 11.4 3.6 5.0 6.6 351% 10.4 1.8 2.5 3.3 767% 9.4 0.9 1.2 1.6 1670% 8.4 important note: the yellow shadowed fields indicate that for thes e input spans with the selected analog gain setting, the quantization noise is higher than 0.1% fso.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 13 of 46 table 1.13 adc resolution characte ristics for an analog gain of 48 analog gain 48 input span [mv/v] min. typ. max. allowed offset (+/- % of span) minimum guaranteed resolution [bits] 10.8 15.0 19.8 3% 13.0 7.2 10.0 13.2 38% 12.4 4.3 6.0 7.9 107% 11.7 2.9 4.0 5.3 194% 11.1 1.8 2.5 3.3 351% 10.4 1.0 1.4 1.85 678% 9.6 0.72 1.0 1.32 976% 9.1 important note: the yellow shadowed fields indicate that for thes e input spans with the selected analog gain setting, the quantization noise is higher than 0.1% fso. table 1.14 adc resolution characte ristics for an analog gain of 96 analog gain 96 input span [mv/v] min. typ. max. allowed offset (+/- % of span) minimum guaranteed resolution [bits] 4.3 6.0 7.9 21% 12.7 2.9 4.0 5.3 64% 12.1 1.8 2.5 3.3 142% 11.4 1.0 1.4 1.85 306% 10.6 0.72 1.0 1.32 455% 10.1
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 14 of 46 2 circuit description 2.1. signal flow and block diagram zmdi?s series of resistive bridge sens or interface ics were specifically designed as cost-effective solutions for sensing in building automation, automotive * , industrial, office automation, and white goods applications. the ZSSC3008 employs a low-power 14-bit analog-to-digital c onverter (adc, a2d, a-to-d) and an on-chip dsp core with eeprom to precisely calibrate the bridge output signal. three selectable outputs, two analog and one digital, offe r the ultimate in versatility across many applications. the ZSSC3008 rail-to-rail ratiometric analog v out signal (0v to ~5 v v out @ v dd =5v) suits most building automation and automotive requirements (12-bit resolution). typical o ffice automation and white goods applications require the 0 to ~1v v out signal, which in the ZSSC3008 is referenced to the internal bandgap. ZSSC3008 is capable of running in high-voltage (5.5-30v) systems when combined with an external jfet. direct interfacing to ? p controllers is facilitated via zmdi?s single-wire serial zacwire? digital interface. figure 2.1 ZSSC3008 block diagram * not aec-q100-qualified.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 15 of 46 2.2. analog front end 2.2.1. bridge supply the voltage-driven bridge is usually connected to v dd and ground. as a power savings feature, the ZSSC3008 also includes a switched transistor to interrupt the bri dge current via pin 1 (bsink). the transistor switching is synchronized to the analog-to-digital conversion and releas ed after finishing the conversi on. to use this feature, connect the low supply of the bridge to bsink instead of ground. depending on the programmable update rate, the averag e current consumption (including bridge current) can be reduced to approximately 20%, 5% or 1%. 2.2.2. preamp block the differential signal from the bridge is amplified through a chopper-stabilized instrument ation amplifier with very high input impedance designed for low noise and low drift. this pre-amp provid es gain for the differential signal and re-centers its dc to v dd /2. the output of the pre-amp block is f ed into the adc. the calibration sequence performed by the digital core includes an auto-zero sequenc e to null any drift in the pre-amp over temperature. the pre-amp can be set to a gain of 6, 24, 48 or 96 through eeprom. the inputs to the pre-amp from (vbn/vbp pins) can be reversed via an eeprom configuration bit. 2.2.3. analog-to-digital converter (adc) a 14-bit/1ms 2 nd order charge-balancing adc is used to convert si gnals coming from the pre-amp. the converter, designed in full differential switched-capacitor technique, is used for converting the various signals in the digital domain. this principle offers the following advantages: ? high noise immunity because of the diffe rential signal path and integrating behavior ? independence from clock frequency drift and clock jitter ? fast conversion time due to second order mode four selectable values for the zero point of the input voltage allow the conversion to adapt to the sensor?s offset parameter. with the reverse input polarity mode and t he negative digital gain options, this results in seven possible zero point adjustments (not ei ght because the -1/2,1/2 offset setting is the same regardless of gain polarity). the conversion rate varies with the programmed update ra te. the fastest conversation rate is 1k samples/s and the response time is then 1ms. based on a best fit, the integral nonlinearity (inl) is less than 4 lsb 14bit .
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 16 of 46 2.3. digital signal processor a digital signal processor (dsp) is used for processing the converted bridge data for output on the digital channel. the digital core reads correction coefficients fr om eeprom and can correct for the following: ? bridge offset ? bridge gain ? a single second order effect (sot) (second order term) the eeprom contains a single sot term that can be applied to correct 2 nd order behavior of the bridge meas- urement. the correction formula for the bridge reading is represented as a two step process as follows: (1) )b_offset raw_br(b_gainzb ? ?? )zbsot25.1(zbbr ??? (2) where: br = corrected bridge reading that is output as digital or analog on sig tm pin zb = intermediate result in the calculations br_raw = raw bridge reading from adc gain_b = bridge gain term offset_b = bridge offset term sot = second order term note for solving equation (1) the following condition must be met: bgainbrrawbr _/ _ ? if this conditio n is not met, the analog pre-amp gain must be set to a smaller value because a negative offset_b is not supported. 2.3.1. eeprom the eeprom contains the calibration c oefficients for gain and offset, etc., and the configuration bits, such as output mode, update rate, etc. the ZSSC3008 also offe rs 3 user-programmable storage bytes for module traceability. when programming the eepr om, an internal charge pump voltage is used; therefore a high voltage supply is not needed. the eeprom is implemented as a shift register. during an eeprom read, the contents are shifted 8 bits before each transmission of one byte occu rs. the charge pump is internally regulated to 12.5 v, and the programming time is 6ms. see section 2.6.1 regarding eeprom signatures for verifying eeprom integrity. note: eeprom writing can only be perf ormed at temperatures lower than 85oc.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 17 of 46 2.3.2. one-wire interface - zacwire? the ic communicates via a one-wire serial interface. t here are different commands available for the following: ? reading the conversion result of the adc (get_br_raw) ? calibration commands ? reading from the eeprom (dump of entire contents) ? writing to the eeprom (trim setting, configuration, and coefficients) 2.4. output stage 2.4.1. digital to analog converter (output dac) with programmable clipping limits a 12-bit dac based on sub-ranging resistor strings is us ed for the digital-to-analog output conversion in the analog ratiometric and absolute analog voltage modes. options during calibration configure the system to operate in either of these modes. the design allows for excellent testability as well as low power co nsumption. the dac allows programming a lower and upper clipping limit for the output signal (analog and digital). the internal 14-bit calculated bridge value is compared against the 14-bit va lue formed by {11,up_clip_lim[6:0],11111} for the upper limit and {00,low_clip_lim[6:0],00000} for the lower limit. if the calculated bridge value is higher than the upper limit or less than the lower limit, the analog output value is clipped to this value; otherwise it is output as is. example for the upper clipping level: if the up_clip_lim[6:0] = 0000000, then the 14-bit value used for clipping threshold is 11000000011111. this is 75.19% of full scale. since there are 7 bits of upper clipping limit, there are 127 possible values between 75.19% and 100%. theref ore the resolution of the clipping limits 0.195%. example for the lower clipping level: if the low_clip_lim[6:0] = 1111111, then the 14-bit value used for clipping threshold is 00111111100000. this is 24.8% of fu ll scale. since there are 7 bits of lower clipping limit, there are 127 possible values between 0 and 24.8%. therefore the resolution of the lower clipping limit is 0.195%. figure 2.2 shows the data timing of the dac out put for the update rate s etting 00. figure 2.2 dac output timing for highest update rate
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 18 of 46 2.4.2. output buffer a rail-to-rail op amp configured as a unity gain buffer can drive resistive loads (whether pull-up or pull-down) as low as 5k ? and capacitances up to 15nf (for pure analog output). in addition, to limit the error due to amplifier offset voltage, an error com pensation circuit is included that tracks and reduces offset voltage to < 1mv. the output of the ZSSC3008 output can be permanently shorted to vdd or vss without damaging the device. the output driver contains a current-limiti ng block that detects a hard short and lim its the current to a safe level. the short circuit protection current can vary from a minimum of 3ma to a maximum of 40ma depending on operating conditions. output short circuit protection can be enabled via diag_cfg (eeprom [102:100]). enabling this protection is recommended when using the analog output. 2.4.3. voltage reference block a linear regulator control circuit is included in the voltage reference block to interface with an external jfet to allow operation in systems where the supply voltage exceeds 5.5v. this circ uit can also be used for over-voltage protection. the regulator set point has a coarse adjustment controlled by the jfet_cfg eeprom bits that can adjust the set point around 5.0 or 5.5v (see table 3.5 for bit locations and section 2.3.1 regarding writing to the eeprom.). the 1v trim setting (see bel o w) can also act as a fine adjust for the regulation set point. the 5v reference can be trimmed within +/-15mv. note: if using the external jfet for over-voltage protection purposes (i.e., 5v at jfet drain and expecting 5v at jfet source), there will be a voltage drop across the jf et; therefore ratiometricity will be slightly compromised depending on the rds(on) of the chosen jfet. a vishay j 107 is the best choice because it has only an 8mv drop worst case. if using as regulation instead of over-voltage, a mmbf4392 or bss169 also works well. the voltage reference block uses the absolute reference voltage provided by the bandgap to produce two regulated on-chip voltage references. a 1v reference is used for the output dac high reference when the part is configured in 0-1v analog output mode. for this reas on, the 1v reference must be very accurate and includes trim so that its value can be trimmed within +/- 3mv of 1.00v. the 1v reference is also used as the on-chip reference for the jfet regulator block. the regulation se t point of the jfet regulator can be fine tuned using the 1v trim.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 19 of 46 the reference trim setting is selected with the 1v_trim/jfet_trim bits in eeprom. see table 3.5 for bit locat ions. table 2.1 shows the order of trim codes with 0111 for th e lowest reference voltage and 1000 for the highest reference voltage. important: optimal reference trim is determined during wafer-level testing and final package testing. back-up copies of these bits are stored in bits in the cust_id0 bits for applications requiring ac curate references. in this case, see section 5 for important notes and instructions for verify ing the integrity of the 1v_trim/jfet_trim bits and if necessary, restoring the value from the cust_id0 bits before calibration. table 2.1 1v reference trim (1v vs. trim for nominal process run) order 1vref/ 5vref_trim3 1vref/ 5vref_trim2 1vref/ 5vref_trim1 1vref/ 5vref_trim0 highest reference voltage 1 0 0 0 ... 1 0 0 1 ... 1 0 1 0 ... 1 0 1 1 ... 1 1 0 0 ... 1 1 0 1 ... 1 1 1 0 ... 1 1 1 1 ... 0 0 0 0 ... 0 0 0 1 ... 0 0 1 0 ... 0 0 1 1 ... 0 1 0 0 ... 0 1 0 1 ... 0 1 1 0 lowest reference voltage 0 1 1 1 2.5. clock generator / power-on reset (clkpor) if the power supply exceeds 2.5v (maxim um), the reset signal de-asserts and the clock generator starts working at a frequency of approximately 512khz (20%). the exact value only influences the conversion cycle time and communication to the outside world but not the accuracy of signal processing. in addition, to minimize the oscillator error as the v dd voltage changes, an on-chip regulator is used to supply the oscillator block.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 20 of 46 2.5.1. trimming the oscillator settings for the osc_trim bits in eeprom fine-tune the oscillator frequency. see table 3.5 for bit locations and table 2.2 for possible settings. the default value is 0 h to ensure communication on start-up. important: optimal oscillator trimming is determined during wafer-level testing and final package testing, and this part-specific factory value, which can be copied to osc_ trim, is stored in bits in the cust_id1 and cust_id2 eeprom bits for applications requiring optimal response time. in th is case, see section 5 for important notes and instru ctions for copying these optimal values to the os c_trim bits before calibration. it is strongly recommended that only the default value or the factory trim value be used because zacwire tm communication is not guaranteed at different oscillator frequencies. table 2.2 oscillator trimming osc_trim bits delta frequency (khz) 100 +385 101 +235 110 +140 111 +65 000 nominal 001 -40 010 -76 011 -110 example: programming 011 b ? the trimmed frequency = nominal value - 110 khz. 2.6. diagnostic features the ZSSC3008 offers a full suite of diagnostic features to ensure robust system operat ion in the most ?mission- critical? applications. if the part is programmed in ratiometric output mode, then diagno stic states are indicated by an output below 2.5% of vdd or a bove 97.5% of vdd. if the part is progr ammed in digital output mode, then diagnostic states will be indicated by a transmission with a generated parity error. diagnostics are not supported in 0-1v output mode. table 2.3 gives a summary of the diagnostic features, which are explained in detail in the following sections. eeprom s ettings that control diagnos tic functions are given in section 3.5 .
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 21 of 46 table 2.3 summary of diagnostic features detected fault analog diagnostic level zacwire tm diagnostic delay in detection eeprom signature lower generates parity error 10ms after power-on loss of bridge positive upper generates parity error 2ms loss of bridge negative upper generates parity error 2ms open bridge connection upper generates parity error 2ms bridge input short upper generates parity error 2ms loss of vdd lower transmissions stop dependent on r l and c l loss of vss upper transmissi ons stop dependent on r l and c l 2.6.1. eeprom integrity the contents of the eeprom are protected by an 8-bit lfsr signature (linear feedback shift register). this sig- nature is regenerated and stored in eeprom every time eeprom contents are changed. this signature is gen- erated and checked for a match after power-on-reset pr ior to entering normal operation mode. if the generated signature fails to match, the part w ill output a diagnostic state on the output. in addition to an extensive temporal and code interlock mechanism used to prevent fa lse writes to the eeprom, the ZSSC3008 offers an eeprom lock mechanism for hi gh-security applications. when eeprom bits 105:103 are programmed with ?011? or ?110,? this 3-bit field will permanently disable the vpp charge pump and will not allow further writes to the eeprom. see table 2.3 in section 2.6 for more information. 2.6.2. sensor connection check four dedicated comparators permanently check the range of the bridge inputs (bp/bn) to ensure they are within the envelope of 0.8v to 0.85 ? vdd during all conversions. the two sensor inputs have a switched ohmic path to ground and if left floating, would be discharged. if any of the wires connecting the bridge break, this mechanism will detect it and put the asic in a diagnostic state. this same diagnostic feature can also detect a short between bp/bn. see table 2.3 in section 2.6 for more information. 2.6.3. sensor short check if a short occurs between bp/bn (bridg e inputs), it would normally produce an in-range output signal and there- fore would not be detected as a fault. this diagnostic mode, if enabled, will deliberately look for such a short. after the measurement cycle of the bri dge, it will deliberately pull the bp bridge input to ground for 4 ? sec. at the end of this 4 ? sec window, it will check to see if the bn input ?follo wed? it down below the 0.8v comparator checkpoint. if so, a short must exist between bp/bn, and the part will output a diagnostic state. the bridge will have a minimum of 480 ? sec recovery time prior to the next measurement. see table 2.3 in section 2.6 for more information.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 22 of 46 2.6.4. power loss detection if the power or gnd connection to the module containing the sensor bridge and asic is lost, the asic will output a diagnostic state if a pull-up or pull-down terminating resistor greater than or equal to 5k ? is connected in the final application. this diagnostic mode only works when the part is configured in analog output mode. see table 2.3 in section 2.6 for more information. 3 functional description 3.1. general working mode the command/data transfer takes place vi a the one-wire sig? pin using the zacwire tm serial communication protocol. after power-on, the ic waits for 3ms (the command window) for the start_cm command. without this command, the normal operation mode (nom) st arts. in this mode, raw bridge values are converted, and the corrected values are presented on the output in anal og or digital format depending on the configuration stored in eeprom. command mode (cm) can only be entered during the 3ms command window after power on. if the ic receives the start_cm command during the command window, it remains in the cm. the cm allows changing to one of the other modes via command. after command start_rm, the ic is in the raw mode (rm). without correction, the raw values are transmitted to the digital output in a predef ined order. the rm can only be stopped by power off. the rm is used by the calibration software for collection of raw bridge data so the correction coefficients can be calculated. if diagnostic features are enabled and a diagnostic fault is detected, diagnostic states are indicated as follows depending on the programmed mode: ? in analog output mode: diagnostic states are indicated by an output below 2.5% of vdd or above 97.5% of vdd. ? in digital output mode: diagnostic states will be in dicated by a transmission wi th a generated parity error. for more details see section 2.6 .
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 23 of 46 normal operation mode start_nom power on command mode raw mode no commands possible. measurement cycle. conditioning calculations (corrected bridge). depending on the configuration, the sig tm pin is - 0 v to 1 v, - rail-to-rail ratiometric, or - digital output. diagnostic functions. measurement cycle stopped. full command set. command routine will be processed after each command. measurement cycle. sig tm pin provides raw bridge data in the format: - bridge_high (1 st byte) - bridge_low (2 nd byte) start_rm command window (3 ms); send start_cm start_cm no command power off diagnostic state* ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 23 of 46 figure 3.1 general working mode normal operation mode start_nom power on command mode raw mode no commands possible. measurement cycle. conditioning calculations (corrected bridge). depending on the configuration, the sig tm pin is - 0 v to 1 v, - rail-to-rail ratiometric, or - digital output. diagnostic functions. measurement cycle stopped. full command set. command routine will be processed after each command. measurement cycle. sig tm pin provides raw bridge data in the format: - bridge_high (1 st byte) - bridge_low (2 nd byte) start_rm command window (3 ms); send start_cm start_cm no command power off diagnostic state* error detection * s ee section 2.6 .
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 24 of 46 3.2. zacwire? communication interface 3.2.1. properties and parameters table 3.1 pin configuration and latch-up conditions no. parameter symbol min typ max unit comments 1 pull-up resistor (on-chip) r zac,pu 30 k ? on-chip pull-up resistor switched on dur- ing digital output mode and during com- mand mode (first 3 ms after power up) 2 pull-up resistor (external) r zac,pu_ext 150 ? if the master communicates via a push- pull stage, no pull-up resistor is needed; otherwise, a pull-up resistor with a value of at least 150 ? must be connected. 3 zacwire? rise time t zac,rise 5 s any user rc network included in sig? path must meet this rise time 4 zacwire? line resistance 1) r zacload 3.9 k ? also see section 1.3 , table 1.9. 5 zacwire? load capacitance 1) c zac,load 0 1 15 nf also see section 1.3 , table 1.9. 6 voltage low level v zac,low 0 0.2 v dd rail-to-rail cmos driver 7 voltage high level v zac,high 0.8 1 v dd rail-to-rail cmos driver 1) the rise time must be t zac,rise = 2 ? r zacload ? c zacload ? 5 ? s . if using a pull-up resistor instead of a line resistor, it must meet this specification. the absolute maximum for c zacload is 15nf. 3.2.2. bit encoding figure 3.2 manchester duty cycle bit window 104.2sec @ 9.6 khz baud 40 sec @ 26khz baud start bit logic 1 logic 0 start bit = 50% duty cycle used to set up strobe time logic 1 = 75% duty cycle logic 0 = 25% duty cycle stop time the zacwire? bus will be held high for 32 s (nominal) between consecutive data packets regardless of baud rate.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 25 of 46 3.2.3. write operation from master to ZSSC3008 the calibration master sends a 19-bit packet frame to the ic. figure 3.3 19-bit write frame p 5 4 3 2 1 0 s command byte data byte s p 2 start bit parity bit of command or data byte command bit (example: bit 2) 7 6 p 5 4 3 2 1 0 7 6 2 data bit (example: bit 2) 19-bit frame (write) the incoming serial signal will be sampled at a 512 khz clock rate. this protocol is very tolerant to clock skew, and can easily tolerate baud rates in the 6 khz to 48 khz range. 3.2.4. ZSSC3008 read operations the incoming frame will be checked for proper parity on both command and data bytes, as well as for any edge time-outs prior to a full frame being received. once a command/data pair is received, the ZSSC3008 w ill perform that command. after the command has been successfully executed by the ic, the ic will acknowledge succ ess by a transmission of an a5 h -byte back to the master. if the master does not receive an a5 h transmission within 130 ms of issuing the command, it must assume the command was either improper ly received or could not be executed. figure 3.4 read acknowledge s data byte s p start bit parity bit of data byte data bit (low) p 1 0 0 1 0 1 1 0 1 data bit (high) 1 data byte packet (10-bit byte a5 h ) 0
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 26 of 46 the ZSSC3008 transmits 10-bit bytes (1 start bit, 8 data bi ts, 1 parity bit). during calibration and configuration, transmissions are normally either a5 h or data. a5 h indicates successful completion of a command. during normal operation mode, if the part is configured for digital output of the bridge reading, it first transmits the high byte of bridge data, followed by the low byte. the bridge data is 14 bits in resolution, so the upper two bits of the high byte are always zero-padded. there is a 32 s stop time when the bus is held high between bytes in a packet. figure 3.5 digital output (nom) bridge readings 2 data byte packet (digita l bridge output ) p 7 6 5 4 3 2 1 0 stop s p 0 0 5 4 3 2 1 0 s data byte bridge high data byte bridge low s stop 2 p start bit parity bit of data byte data bit (example: bit 2) 32s the eeprom transmission occurs in a packet with 20 data bytes, as shown in figure 3.6 . figure 3.6 read eeprom contents there is a variable idle time between packets. thi s idle time varies with the update rate setting in eeprom.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 27 of 46 figure 3.7 transmission of a number of data packets the table below shows the idle time between packets versus the update rate. this idle time can vary by a nominal +/-15% between parts and over a temp erature range of -40oc to 125oc. table 3.2 special measurement/idle time between packets versus update rate update rate setting idle time between packets special measurement 00 1ms every 128 bridge measurements 01 4.85ms every 64 bridge measurements 10 22.5ms every 16 bridge measurements 11 118ms every 8 bridge measurements transmissions from the ic occur at one of two speeds depending on the update rate programmed in eeprom. if the user chooses one of the two fastest update rates (1 ms or 5 ms) then the baud rate of the digital transmission will be 32khz (minimum 26khz ). if, however, the user chooses one of the two slower update rates (25ms or 125ms), then the baud rate of the digital trans mission will be 8khz (maximum 9.6khz). the total transmission time is shown in table 3.3 . table 3.3 total transmission time for different update rate settings update rate baud rate* idle time transmission time ? bridge readings 1ms (1khz) 32khz 1.0ms 20.5 bits 31.30s 1.64ms 5ms (200hz) 32khz 4.85m s 20.5 bits 31.30s 5.49ms 25ms (40hz) 8khz 22.5ms 20.5 bits 125.00s 25.06ms 125ms (8hz) 8khz 118.0ms 20.5 bits 125.00s 120.56ms * typical values. minimum baud rate for 1 ms or 5 ms: 26khz; maximum baud rate for 25 ms or 125 ms: 9.6khz. the 3rd column in table 3.2 shows the timing for the special measurem ents in t he different update rate modes. for lower update rates, the output is followed by a power-down as shown in figure 3.8 . s p p stop s p s p s idle time 0 0 5 4 3 2 1 0 7 6 5 4 3 2 1 0 0 0 5 4 3 2 1 0 7 6 5 4 3 2 1 0 0 0 5 4 idle time idle time 1 0 p s 2 packet transmission (this example shows 2 data packets ) stop
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 28 of 46 figure 3.8 zacwire? output timing for lower update rates zacwire tm output calculation 160 ? s settling time 64 ? s power-on settling 128 ? s power down (determined by update rate) adc conversion 768 ? s calculation 160 ? s zacwire tm output it is easy to program any standard microcontroller to comm unicate with the ZSSC3008. zmdi can provide sample code for a microchip pic microcontroller. 3.2.5. high level protocol the ZSSC3008 will listen for a command/ data pair to be transmitted for the 3 ms after the de-as sertion of its internal power on reset (por). if a transmission is not rece ived within this time frame, then it will transition to normal operation mode (nom). in the nom, it will output bridge data in 0-1v analog, rail-to-rail ratiometric analog, or digital depending on how the part is currently configured. if the ZSSC3008 receives a start_cm command within the first 3 ms after the de-assertion of por, then it will go into command mode (cm). in this mode, calibration/c onfiguration commands will be executed. the ZSSC3008 will acknowledge successful execution of commands by tr ansmission of a5h. the calibrating/configuring master will know a command was not successfully executed if no response is received after 130ms of issuing the command. once in command interpreting/executing mode, the ZSSC3008 will stay in this mode until power is removed or a start nom (start normal operation mode) command is received. the start_cm command is used as an interlock mechanism to prevent a spurious entry into command mode on power up. the first command received within the 3ms window of por must be a start_cm command to enter into command interpreting mode. any other commands will be ignored.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 29 of 46 3.3. command/data bytes encoding the 2-byte command sent to the ZSSC3008 consists of 1 byte of command information and 1 byte of data information. regardless of whether the comm and requires data or not, 2 bytes must be sent. table 3.4 lists all the comm and/data pairings. (x=don?t care.) table 3.4 command/data bytes encoding command byte data description 00 h xx h read eeprom command via sig? pin. ? 20 h 5x h dac ramp test mode. gain_b[13:3] contai ns the starting point, and the increment is (offset_b/8). the increment will be added every 125sec. trim/configure: 3 rd nibble determines what is trimmed/configured. the 4 th nibble is data to be programmed. 3 rd nibble 4 th nibble description 0 h data trim oscillator. least significant 3 bits of data used. 1 h data trim 1v reference. least significant 4 bits of data used. 2 h data offset mode. least signif icant 4 bits of data used. 3 h data set output mode. least significant 2 bits used. 4 h data set update rate. least significant 2 bits used. 5 h data configure jfet regulation 7 h data program eeprom bits [99:96] (pamp_gain) d h 3 h or 6 h program eeprom bits [105:103]: eeprom locked! all others: eeprom unlocked. 30 h e h data program eeprom bits [102:100] diag_cfg ? 40 h 00 h start nom => ends command mode; tr ansition to normal operation mode. 40 h 10 h start_rm = start the raw mode (rm) in this mode, if gain_b = 800h, then the digita l output will simply be the raw values of the adc for the bridge reading. 50 h 90 h start_cm => start the command mode; us ed to enter command interpret mode. 60 h yy h program sot (2 nd order term) 80 h yy h program gain_b upper 7-bits (set the msb to 0.) 90 h yy h program gain_b lower 8-bits a0 h yy h program offset_b upper 6-bits (set the two msbs to 0.) b0 h yy h program offset_b lower 8-bits 08 h yy h program upper clipping limit (set the msb to 0.) ? for more details, refer to section 3.7. ? for more details, refer to section 3.5.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 30 of 46 command byte data description 18 h yy h program lower clipping limit (set the msb to 0.) 28 h yy h program cust_id0 38 h yy h program cust_id1 48 h yy h program cust_id2 3.4. calibration sequence although the ZSSC3008 can work with many different types of resistive bridges, assume a pressure bridge is being used for the following discussion on calibration. calibration essentially involves collecti ng raw bridge data from the ic for different known pressures. this raw data can then be processed by the calibrati on master (typically a pc) to comput e the coefficients, and the calculated coefficients can then be written to the ic. zmdi can provide software and hardware with samples to perform the calibration. there are three main steps to calibration: 1. assigning a unique identification to the ic. this identification is programmed in eeprom and can be used as an index into the database stored on the ca libration pc. this database will contain all the raw values of bridge readings for that part, as well as the known pressure (for this application) that the bridge was exposed to. this uniqu e identification can be stored in a concatenation of the following eeprom registers: cust_id0, cust_id1, cu st_id2. these registers can also form a permanent serial number. 2. data collection. data collection involves getting raw data from the bridge at different known pressures. this data is then stored on the calibration pc using the unique identification of the ic as the index to the database. 3. coefficient calculation and write. once enough dat a points have been collected to calculate all the desired coefficients then the coefficients can be calcul ated by the calibrating pc and written to the ic. step 1 ? assigning unique identification assigning a unique identification number is as simple as using the commands program cust_id0, program cust_id1 and program cust_id2. these three 8-bit regi sters allow for more than 16 million unique devices. gain_b must be programmed to 800 h (unity). step 2 ? data collection the number of unique pressure points that calibration must be performed at depends on the customer?s needs. the minimum number of calibration points required is two or three, depending on the precision desired and the behavior of the resistive bridge in use. ? 2-point calibration can be used if only a gain and offset term are needed. ? 3-point calibration can be used to also obtain 2 nd order correction.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 31 of 46 to acquire raw data from the part, set ZSSC3008 to enter raw mode. this is done by issuing a start_cm (start command mode 5090h) command/data pair to the ic followed by a start_rm (start raw mode 4010 h ) command/data pair with the lsb of the upper data nibble set. now if the gain_b term has been set to unity (800 h ), then the part will be in the raw m ode and will output raw data on its sig tm pin instead of corrected bridge data. capture several of these data points with the user ?s calibration system (capturing 16 is recommended) and average them. store these raw data in the database al ong with the known pressure. the output format during raw mode is bridge_high, bridge_low. each of these is an 8-bit quantity. the upper 2-bits of bridge_high are zero filled. step 3 ? coefficient calculations the math to perform the coefficient calculation is very complicated and will not be discussed in detail. there is a rough overview of the coefficients in the ?calibration math? section 3.6 . zmdi will provide software to perform the c oefficient calculation. after the coefficients are calculat ed, the final step is to write them to the eeprom of the ZSSC3008.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 32 of 46 3.5. eeprom bits table 3.5 shows the bit order and default settings for the eeprom, which are programm ed through the serial interface. see section 5 for important information for die/wafer customers. table 3.5 ZSSC3008 eeprom bits eeprom range description default settings notes 2:0 osc_trim 0 h this default setting minimizes risk of communication failure on start-up. (actual part-specific factory values for osc_trim are initially stored in bits in cust_id1 and cust_id2 for appli- cations requiring op- timal response time. see section 5 for important notes.) see section 2.5 for details on oscillator trim. 100 = > fastest 101 => 3 clicks faster than nominal 110 => 2 clicks faster than nominal 111 => 1 click faster than nominal 000 => nominal 001 => 1 click slower than nominal 010 => 2 clicks slower than nominal 011 => slowest 6:3 1v_trim/jfet_trim ssss bin where ?s? is the part- specific factory bit setting for the reference voltage trim value. (back-up copies are stored in cust_id0 for applications re- quiring accurate references. see section 5 for impor- tant notes.) see table 2.1 in the ?voltage reference block? section. 10:7 a2d_offset 3 h the upper two bits are flip polarity and invert bridge input (negative gain) respectively. if both are used in conjunction, negative offset modes can be achieved. 00 => normal polarity, positive gain 01 => normal polarity, negative gain 10 => flip polarity, positive gain 11 => flip polarity, negative gain the lower two bits form the adc offset selection. offset selection: 11 => [-1/2,1/2] mode bridge inputs 10 => [-1/4,3/4] mode bridge inputs 01 => [-1/8,7/8] mode bridge inputs 00 => [-1/16,15/16] mode bridge inputs
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 33 of 46 eeprom range description default settings notes 12:11 output_select 2 h 00 => not recommended! digital (3 bytes with parity) bridge high {00,[5:0]},bridge low [7:0] 3 rd byte =00 h 01 => 0-1v analog (requires 1khz update rate) 10 => rail-to-rail ratiometric (requires 1khz update rate) 11 => digital (2 bytes with parity) bridge high {00,[5:0]} bridge low [7:0] 14:13 update_rate 2 h 00 => 1 msec (1khz) 01 => 5 msec (200hz) 10 => 25 msec (40hz) 11 => 125 msec (8 hz) 16:15 jfet_cfg 3 h 00 => no jfet regulation (lower power) 01 => no jfet regulation (lower power) 10 => jfet regulation centered around 5.0v 11 => jfet regulation centered ar ound 5.5v (i.e., over-voltage protection) 31:17 gain_b 198 h bridge gain (also see bits 10:7 ): gain_b[14] => multiply x 8 gain_b[13:0] => 14-bit unsigned number representing a number in the range [0,8) 45:32 offset_b 0 h unsigned 14-bit offset for bridge correction 87:46 reserved 0 h program to 0. 95:88 sot 0 h 2 nd order term. this term is a 7-bit magnitude with sign. sot[7] = 1 ? negative sot[7] = 0 ? positive sot[6:0] = magnitude [0-127] 99:96 pamp_gain 1 h bits [99:96] = pre-amp gain 0000 => 6 0001 => 24 (default setting) 0010 => 48 0011 => 96 all others prohibited 102:100 diag_cfg 7 h this 3-bit term applies to diagnostic features diag_cfg[2] ? enable output short circuit protection. diag_cfg[1] ? enable sensor short checking. diag_cfg[0] ? enable sensor connection checking. 105:103 eeprom_lock 0 h eeprom lock 011 or 110 => locked all other => unlocked when eeprom is locked, the internal charge pump is disabled and the eeprom can never be programmed again.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 34 of 46 eeprom range description default settings notes 112:106 up_clip_lim 7f h 7-bit value used to select an upper clipping limit for the output. it affects both analog and digital output. the 14-bit upper clipping limit value is comprised of {11,up_clip_lim[6:0],11111}. 127 different clipping levels are selectable between 75.19% and 100% of vdd. 119:113 low_clip_lim 0 h 7-bit value used to select a lower clipping limit for the output. it affects both analog and digital output. the 14-bit lower clipping limit value is comprised of {00,low_clip_lim[6:0],00000}. 127 different clipping levels are selectable between 0% and 24.8% of vdd. 127:120 cust_id0 ss bin where ?s? is a part- specific factory bit setting. during factory test- ing, two back-up copies of the optimal setting for the 1v_trim/jfet_trim bits are stored in [123:120] and in [127:124]. see im- portant notes in section 5. customer id byte 0 can be used to store a customer part identification number. caution: if the application requires accurate voltage references, do not overwrite this byte until completing the procedures in section 5 . 135:128 cust_id1 xsss xsss bin where ?s? is a part- specific factory bit setting and x is ?don?t care.? during factory test- ing, two copies of the optimal setting for the osc_trim bits are stored in [130:128] and in [134:132]. (also in cust_id2.) see im- portant notes in section 5. customer id byte 1 can be used to store a customer part identification number. caution: if the application requires optimal response time, do not overwrite this byte until completing the procedures in section 5 .
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 35 of 46 eeprom range description default settings notes 143:136 cust_id2 xxxx xsss bin where ?s? is a part- specific factory bit setting and x is ?don?t care.? during factory test- ing, a copy of the optimal setting for the osc_trim bits is stored in [138:136]. (also in cust_id1.) see important notes in section 5. customer id byte 2 can be used to store a customer part identification number. caution: if the application requires optimal response time, do not overwrite this byte until completing the procedures in section 5 . 151:144 signature 8-bit eeprom signature. generated through a linear feedback shift register (lfsr). this signature is checked on power-on to ensure integrity of eeprom contents. 3.6. calibration math 3.6.1. correction coefficients all terms are calculated external to the ic and then programmed to the eeprom thr ough the serial interface. table 3.6 correction coefficients coefficient description gain_b gain term used to compensate span of bridge reading offset_b offset term used to compensate offset of bridge reading sot second order term( sot) for bridge measurement 3.6.2. interpretation of binary numbers for correction coefficients br_raw should be interpreted as an unsigned number in the set [0, 16383] with a resolution of 1.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 36 of 46 3.6.2.1. gain_b interpretation gain_b shoul d be interpreted as a number in the set [0, 64]. the msb (bit 14) is a scaling bit that will multiply the effect of the gain_b[13:0] term by 8. the remaining bi ts gain_b[13:0] represent a number in the range of [0,8) with gain_b[13] having a weighting of 4, and each s ubsequent bit has a weighting of ? the previous bit. table 3.7 gain_b [13:0] weightings bit position weighting 13 2 2 = 4 12 2 1 = 2 11 2 0 = 1 10 2 -1 ... ... 3 2 -8 2 2 -9 1 2 -10 0 2 -11 examples: the binary number: 010010100110001 b = 4.6489; gain_b[14] is 0 b , so the number represented by gain_b[13:0] is not multiplied by 8. the binary number: 101100010010110 b = 24.586; gain_b[14] is 1 b , so the number represented by gain_b[13:0] is multiplied by 8. 3.6.2.2. offset_b interpretation offset_b is a 14-bit unsigned binary number. the msb has a weighting of 8192. the following bits then have a weighting of: 4096, 2048, 1024 ? table 3.8 offset_b weightings bit position weighting 13 8192 12 4096 11 2048 . . . 1 2 1 = 2 0 2 0 = 1 for example, the binary number 1111 1111 1100 = 4092.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 37 of 46 3.6.2.3. sot interpretation sot is a 2 nd order term that applies to bridge non-linearity correction. ? resolution: 0.25% @ full scale ? range: +25% @ full scale to -25% @ full scale (saturation in internal arithmetic will occur at greater negative non-linearities.) 3.7. reading eeprom contents the contents of the entire eeprom memory can be read out using the read eeprom command (00 h ). this command causes the ic to output co nsecutive bytes on the zacwire?. a fter each transmission, the eeprom contents are shifted by 8 bits. the bi t order of these bytes is given in table 3.9 . table 3.9 eeprom read order bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 byte 1 offset_b[7:0] byte 2 reserved offset_b[13:8] byte 3 byte 4 byte 5 byte 6 byte 7 reserved byte 8 sot[7:0] byte 9 eeprom_lock[0] diag_cfg[2:0] pamp_gain[3:0] byte 10 up_clip_lim[5:0] eeprom_lock[2:1] byte 11 low_clip_lim[6:0] up_clip_lim[6] byte 12 cust_id0[7:0] byte 13 cust_id1[7:0] byte 14 cust_id2[7:0] byte 15 signature[7:0] byte 16 a2d_offset[0] 1v_trim[3:0] * osc_trim[2:0] * byte 17 jfet_cfg[0] update_rate[1:0] output select[1:0] a2d_offset[3:1] byte 18 gain_b[6:0] jfet_cfg[1] byte 19 gain_b[14:7] byte 20 a5 h * 1v_trim/jfet_trim
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 38 of 46 4 application circuit examples the minimum output analog load resistor is r l = 5k ? . this optional load resistor can be configured as a pull-up or pull-down. if it is configured as a pull-down, it cannot be part of the module to be calibrated because this would prevent proper operation of the zacwire tm . if a pull-down load is desired, it must be added to the system after module calibration. there is no output load capacitance needed. applicable eeprom contents: output_select, jfet_cfg, 1v_trim/jfet_trim. 4.1. three-wire rail-to-rail ratiometric output this example shows an application circuit for rail-to-r ail ratiometric voltage output configuration. the same circuitry is applicable for a 0 to 1v absolute analog output. figure 4.1 rail-to-rail ratiometric voltage output the option al bridge sink allows a power savings of bridge current. the output voltage can be either ? rail-to-rail analog output ratiometric to v dd (vsupply). ? 0 to 1v absolute analog output. the absolute voltage out put reference is trimmable 1v (+/-3mv) in the 1v output mode via a 4-bit eeprom field. (see section 2.4.3 ).
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 39 of 46 4.2. absolute analog voltage output figure 4.2 shows an application circuit for an absolute volt age out put configuration and external jfet regulation for all industry standard applications. figure 4.2 absolute analog voltage output with external jfet regulation the output signal range can be one of the following options: ? 0 to 1 v analog output. the absolute voltage output reference is trimmable: 1 v (+/-3 mv) in the 1 v output mode via a 4-bit eeprom field (see section 2.4.3 ). ? rail-to-rail analog output. the on-chip reference for the jfet regulator block is trimmable: 5 v (15mv) in the ratiometric output mode via a 4-bit eeprom field. (see section 2.4.3 ).
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 40 of 46 4.3. three-wire ratiometric output w ith over-voltage protection the figure below shows an application circuit for a ratiomet ric output. in this application, the jfet is used for voltage protection. jfet_cfg (16:15) in the eeprom are configured to 5.5v. there is an additional maximum error of 8mv caused by the non-zero r on of the limiter jfet. figure 4.3 ratiometric output 4.4. digital output for all three circuits, the output bridge signal can also be digital. for the digital output, no load resistor or load capacity is necessary. no pull down resistor is allowed. if a line resistor or pull-up resistor is used, the require- ment for the rise time must be met ( 5 ? s). the ic output includes an internal pull up resistor of about 30k ? . the digital output can easily be read by firmware from a mi crocontroller, and zmdi can provide the customer with software for developing the interface. 4.5. output resistor/capacitor limits the limits for external components depend on the programmed output mode: ? pure analog output mode (calibration is done before) : the only limit is the minimum load resistance of 5k ? . ? pure digital output mode with end-of-line calibration: the rc time constant of the zacwire? line must have a rise time 5 ? s. ? analog output with digital communication during calibrat ion: the rc time constant of the zacwire? line must have a rise time 5 ? s. warning: any series line resistance forms a voltage divider in conjunction with the pull-up load device. if a series line resistance is needed, choose a low value relative to the pull-up load device.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 41 of 46 5 eeprom restoration if needed, the default settings for the ZSSC3008 (see table 3.5 ) can be reprogrammed as described in section 3 . the followi ng sections describe eeprom content validation and handling dur ing and/or after system assembly. important: during the sawing and dicing process, there is a possibility of the eeprom contents flipping, and prevention cannot be guaranteed. this is primarily a concern for the factory trim settings, which are customized to each part. the eeprom default values programmed during the different test levels have been sele cted so that customer has the option to refresh/reprogram trim bits that might have flipped during sawing or dicing. important: the eeprom lock is stored in the bit range 105:103. a value of 6 h or 3 h will lock the eeprom forever by disabling the charge pump needed for eeprom writing. the comple te contents can also be validated using the eeprom signature stored in bits [151:144], (see ?signature? in table 3.5). 5.1. default eeprom contents during the wafer level test (wafer/dic e delivery) and during final test fo r sop8 packaged parts, the eeprom is programmed with the default values listed in the table 3.5 . duri ng the wafer level test, the osc_trim bits [2:0] and 1v_t rim/jfet_trim trim bits [6:3] are set to die-specific values. 5.1.1. osc_trim the oscillator frequency is trimmed to a value of 512khz20% using the osc_trim bit setting. the 3-bit setting is copied twice to cust_id1[134:132] and [130:128] and then a th ird time to cust_id2[138:136] to ensure the factory settings are retained so that the customer can reprogram these values in the osc_trim bit if needed. based on the most probable trimming, the default values for the osc_trim bits are always set to 0 h during factory testing to guarantee communication even if bits have flipped. 5.1.2. 1v_trim/jfet_trim the 5v reference for the jfet regulation is factory tri mmed during the final test to 5v15mv using the 1v_trim/ jfet_trim bit setting. the 4-bit setting stored in eeprom bits [6:3] is copied twice to the cust_id0 bits [127:124] and [123:120] to ensure the factory settings are retained so that the customer can reprogram these values in the 1v_trim/jfet_trim bits if needed. 5.2. eeprom restoration procedure after module assembly, the eeprom content should be refreshed. if jfet regulation is not used for the cus- tomer?s application and optimized response time is not an important criterion, write the default values shown in table 3.5 to the eeprom bit range [143:7] and retain the existing values in the bit range [6:0]. if jfet regul ation or optimized response time is required, the bit restoration procedure shown in the flow chart in figure 5.1 must be used to keep the factory se ttings programmed during the test ing. if customer oscillator trimming is required, see ZSSC3008_tech_notes_jfet_and_osc_trimming_revx.x .pdf for instructions.) note: the eeprom signature is re-calculat ed and updated after every eeprom writing.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 42 of 46 read eeprom check osc_trim bits [134:132]=[130:128] y n check osc_trim bits [134:132]=[138:136] y n write [134:132] to [2:0] write [134:132] to [2:0] perform new osc_trim check jfet_trim bits [6:3]=[127:124] check jfet_trim bits [6:3]=[123:120] y keep bits [6:3] n y keep bits [6:3] n perform new jfet_trim start cm restore factory trimming? y n write eeprom default values [143:7] n check osc_trim bits [130:128]=[138:136] y write [130:128] to [2:0] check jfet_trim bits [123:120]=[127:124] n y ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 42 of 46 figure 5.1 eeprom validation and restoration procedure read eeprom check osc_trim bits [134:132]=[130:128] y n check osc_trim bits [134:132]=[138:136] y n write [134:132] to [2:0] write [134:132] to [2:0] perform new osc_trim check jfet_trim bits [6:3]=[127:124] check jfet_trim bits [6:3]=[123:120] y keep bits [6:3] n y keep bits [6:3] n perform new jfet_trim start cm restore factory trimming? y n write eeprom default values [143:7] n check osc_trim bits [130:128]=[138:136] y write [130:128] to [2:0] check jfet_trim bits [123:120]=[127:124] n y write [123:120] to[6:3]
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 43 of 46 6 pin configuration and package the standard package of the ZSSC3008 is an sop-8 (3 .81 mm / 150 mil body) with a lead-pitch 1.27 mm / 50 mil. table 6.1 storage and soldering conditions storage and soldering for the sop-8 package parameter symbol conditions min. typ. max. unit ? maximum storage temperature less than 10hrs before mounting t max _ storage 150 ?c minimum storage temperature: t min _ storage store in original packing only -50 ?c maximum dry-bake temperature t drybake ? less than100 hrs total, before mounting 125 ?c soldering peak temperature t peak ? less than 30s (ipc/jedec-std-020 standard) 260 ?c note: also see table 6.1 regarding other storage conditions. figure 6.1 ZSSC3008 pin-out diagram table 6.2 ZSSC3008 pin configuration pin no. name description 1 bsink optional ground connection for bridge ground. used for power savings. 2 vbp positive bridge connection 3 nc no connection 4 vbn negative bridge connection 5 vgate gate control for external jf et regulation/over-voltage protection 6 vdd supply voltage (2.7 to 5.5 v) 7 sig? zacwire? interface (analog out, digital out, calibration interface) 8 vss ground supply
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 44 of 46 7 esd/latch-up-protection all pins have an esd protection of >4000v and a latch-up protection of ? 100 ma or of +8v/ ?4v (to vss/vssa). esd protection referenced to the human body model is tested with devices in sop-8 packages during product qualification. the esd test follows the human body model with 1.5k ? /100pf based on mil 883, method 3015.7. 8 test the test program is based on this datasheet. the final parameters which will be tested during series production are listed in the tables of section 1 . the digital pa rt of the ic includes a scan path, whic h can be activated and controlled during wafer test. further test support for testing of the analog parts on wafer level is included in the dsp. 9 quality and reliability a reliability qualification according to the in- house non-automotive standar d has been performed. 10 customization for high-volume applications, which require an upgraded or downgraded functionality compared to the ZSSC3008, zmdi can customize the circuit design by adding or removing certain functional blocks. for this customization, zmdi has a considerable library of sensor-dedicated circuitry blocks, which enable zmdi to provide a custom solution quickly. pleas e contact zmdi for further information. 11 product ordering codes please contact zmdi sales for additional options. sales code description package ZSSC3008aa2r ZSSC3008 sop8 (150 mil) ? temperature range: -40c to +125c tape and reel ZSSC3008aa2t ZSSC3008 sop8 (150 mil) ? temperat ure range: -40c to +125c tube ZSSC3008kit ZSSC3008 ssc evaluation kit: comm unication board, ssc board, sensor replacement board, evaluation software, usb cable, 5 ic samples kit contact zmdi sales for support and sales of zmdi?s ZSSC3008 mass calibration system.
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 45 of 46 12 related documents document file name ZSSC3008 development kit documentation ZSSC3008_development_kit_revx.x.pdf ZSSC3008 application notes ? in-circuit programming boards ZSSC3008_app_notes_in-circuit_ programming_rev x.x.pdf ZSSC3008 die dimensions and pad coordinates ZSSC3008_tech_notes_die_pads_revx.x.pdf visit zmdi?s website www.zmdi.com or contact your nearest sales office for the latest version of these documents. 13 definitions of acronyms term description adc analog-to-digital converter afe analog front-end buf buffer cm command mode cmc calibration microcontroller dac digital-to-digital converter dnl differential nonlinearity dsp digital signal processor dut device under test esd electrostatic discharge fso full-scale output inl integrated nonlinearity lfsr linear feedback shift register lsb least significant bit mux multiplexer nom normal operation mode owi one-wire interface poc power-on clear por power-on reset level psrr power supply rejection ratio rm raw mode sot second order term ssc sensor signal conditioner
ZSSC3008 sensor signal conditioner with diagnostics data sheet june 14, 2011 ? 2011 zentrum mikroelektronik dresden ag ? rev. 1.11 all rights reserved. the material contained herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. the information furnished in this publication is subject to changes without notice. 46 of 46 14 document revision history revision date description 1.00 february 18, 2011 first release. 1.10 may 5, 2011 revised minimum temperature from -50c to -40c. revised product ordering code for ZSSC3008 with -40c to +125c operating range from ZSSC3008ai2r to ZSSC3008aa2r. minor revision to produc t description. minor edit to section 9 . 1.11 june 14, 2011 update to section 9 . sales and further information www.zmdi.com ssc@zmdi.com zentrum mikroelektronik dresden ag (zmd ag) grenzstrasse 28 01109 dresden germany zmd america, inc. 8413 excelsior drive suite 200 madison, wi 53717 usa zentrum mikroelektronik dresden ag, japan office 2nd floor, shinbashi tokyu bldg. 4-21-3, shinbashi, minato-ku tokyo, 105-0004 japan zmd far east, ltd. 3f, no. 51, sec. 2, keelung road 11052 taipei taiwan phone +49 (0)351.8822.7.772 fax +49(0)351.8822.87.772 phone +1 (608) 829-1987 fax +1 (631) 549-2882 phone +81.3.6895.7410 fax +81.3.6895.7301 phone +886.2.2377.8189 fax +886.2.2377.8199 disclaimer : this information applies to a product under development. its characteristics and specifications are subject to change without notice. zentrum mikroe lektronik dresden ag (zmd ag) assumes no obligation regarding future manufacture unless otherwise agreed to in writing. the information furnished hereby is believed to be true and accurate. however, under no circumstances shall zmd ag be liable to any customer, licensee, or any other third party for any special, indirect, incident al, or consequential damages of any kind or nature whatsoever arising out of or in any way related to the furnishing, performance, or use of this technical data. zmd ag hereby expressly dis claims any liability of zmd ag to any customer, licensee or any other third party, and any such customer, licensee and any other third party hereby waives any liability of zmd ag for any dama ges in connection with or arising out of the furnishing, perfor- mance or use of this technical data, whether based on contract, warranty, tort (including negligence), strict liability, or oth erwise.
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