ltc1706-85 1 170685f applicatio s u descriptio u features typical applicatio u the ltc ? 1706-85 is a precision, digitally programmed resistive ladder which adjusts the output of any 0.8v- referenced regulator. depending on the state of the five vid inputs, an output voltage between 1.05v and 1.825v is programmed in 25mv increments. the ltc1706-85 is designed specifically to program an entire family of linear technology dc/dc converters in full compliance with the intel voltage regulator module (vrm) 8.5 specification. the ltc1706-85 programs the following linear technol- ogy dc/dc converter products: ltc1622, ltc1628, ltc1629, ltc1702, ltc1735, ltc1735-1, ltc1772, ltc1773, ltc1778, ltc1929, ltc3728 and ltc3729. consult factory for additional dc/dc converter products compatible with the ltc1706-85. n server/desktop computers n multiprocessor workstations and servers n multiphase processor power supply n fully compliant with the intel vrm 8.5 vid specification n programs regulator output voltage from 1.05v to 1.825v in 25mv steps n programs an entire family of linear technology dc/dc converters with 0.8v references n 0.25% voltage programming accuracy n built-in 40k pull-up resistors on program inputs n available in msop-10 packaging vid voltage programmer for intel vrm 8.5 1706-85 ta01 r sense1 v in v in 4.5v to 22v v in 4.5v to 22v ltc1629 v os v os + clkout v diffout sgnd eain i th intv cc c out v in tg1 sw1 bg1 pgnd + v out 1.05v to 1.825v up to 80a vid25 vid0 vid1 vid2 vid3 v cc ltc1706-85 gnd sense fb from p r sense2 note: up to six ltc1629s/ltc1929s can be paralleled to deliver as much as 200a r sense3 v in ltc1929 sgnd eain i th v in tg1 sw1 bg1 pgnd r sense4 tg2 sw2 bg2 tg2 sw2 bg2 pllin vid controlled high current 4-phase dc/dc converter (simplified block diagram) , ltc and lt are registered trademarks of linear technology corporation. pentium is a registered trademark of intel corporation.
ltc1706-85 2 170685f input supply voltage (v cc ) ..........................C 0.3v to 7v vid input pins .............................................C 0.3v to 7v sense pin ...................................................C 0.3v to 7v fb pin ..........................................................C 0.3v to 7v operating temperature range (note 3) .. C 40 c to 85 c junction temperature ........................................... 110 c storage temperature range ................. C 65 c to 150 c lead temperature (soldering, 10 sec).................. 300 c order part number ms part marking t jmax = 110 c, q ja = 200 c/w consult ltc marketing for parts specified with wider operating temperature ranges. ltyq LTC1706EMS-85 absolute axi u rati gs w ww u package/order i for atio uu w (notes 1, 2) electrical characteristics the l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at t a = 25 c. 2.7v v cc 5.5v, vid25 = vid0 = vid1 = vid2 = vid3 = nc unless otherwise noted. (note 3) symbol parameter conditions min typ max units v cc operating supply voltage range 2.7 5.5 v i vcc supply current (note 4) 1 10 m a r fb1 resistance between sense and fb l 61014 k w v out(error) output voltage accuracy 1.050 v sense 1.825v l C 0.25 0.25 % r pullup pull-up resistance on vid v diode = 0.6v (note 5) 28 40 56 k w v ih minimum high level input voltage (vid inputs) v cc = 3.3v 2 v v il maximum low level input voltage (vid inputs) v cc = 3.3v 0.8 v i in input leakage current (vid inputs) v cc < vid < 7v (note 5) 0.01 1 m a depending on the number of grounded vid lines. each grounded vid line will draw approximately [(v cc C 0.6)/40]ma. if the vid inputs are left unconnected, they will float to v cc at a rate controlled by parasitic capacitance. until the vid inputs reach their final states, slightly higher i vcc current may be observed. (see the operation section for more detail.) note 5: each built-in pull-up resistor attached to the vid inputs also has a series diode connected to v cc to allow input voltages higher than the v cc supply without damage or clamping. (see operation section for further details.) note 1: absolute maximum ratings are those values beyond which the life of a device may be impaired. note 2: all voltages are with respect to gnd pin. note 3: the ltc1706-85 is guaranteed to meet performance specifications from 0 c to 70 c. specifications over the C 40 c to 85 c operating temperature range are assured by design, characterization and correlation with statistical process controls. note 4: supply current is specified with all vid inputs floating. due to the internal pull-ups on the vid pins, the supply current will increase 1 2 3 4 5 vid25 vid0 vid1 vid2 v cc 10 9 8 7 6 fb gnd nc vid3 sense top view ms package 10-lead plastic msop
ltc1706-85 3 170685f typical perfor a ce characteristics uw typical error % vs output voltage typical error % vs temperature r fb1 vs temperature vid pullup current vs temperature supply current vs temperature supply current vs supply voltage output voltage (v) 1.0 error (%) 1706-85 g01 0.25 0 0.25 1.2 1.4 1.6 1.8 t a = 25 c temperature ( c) 50 0 50 100 error (%) 1706-85 g02 0.25 0 0.25 v out = 1.825v v out = 1.325v v out = 1.05v temperature ( c) 50 0 50 100 r fb1 (k ) 1706-85 g03 10.10 10.05 10.00 9.95 9.90 temperature ( c) 50 0 50 100 vid pull-up current ( a) 1706-85 g04 70 65 60 55 v cc = 3.3v vid pin under test = 0v temperature ( c) 50 0 50 100 supply current ( a) 1706-85 g05 1.0 0.5 0 v cc = 2.7v v cc = 5v all vid inputs open v cc = 3.3v supply voltage (v) 2.5 4.5 3.5 3.0 4.0 5.0 5.5 6.0 supply current ( a) 1706-85 g06 1.0 0.5 0 all vid inputs open t a = 25 c
ltc1706-85 4 170685f vid25 (pin 1): programming input. gnd = low, v cc or float = high. refer to table 1 for programming information. connect to associated vid pin of m p. vid0 (pin 2): programming input. gnd = low, v cc or float = high. refer to table 1 for programming information. connect to associated vid pin of m p. vid1 (pin 3): programming input. gnd = low, v cc or float = high. refer to table 1 for programming information. connect to associated vid pin of m p. vid2 (pin 4): programming input. gnd = low, v cc or float = high. refer to table 1 for programming information. connect to associated vid pin of m p. v cc (pin 5): power supply voltage. may range from 2.7v to 5.5v. pi fu ctio s uuu sense (pin 6): regulator output voltage. connect di- rectly to regulator output sense node or v diffout when used with the ltc1929 or ltc1629. vid3 (pin 7): programming input. gnd = low, v cc or float = high. refer to table 1 for programming information. connect to associated vid pin of m p. nc (pin 8): no connect. gnd (pin 9): ground. connect to regulator signal ground. fb (pin 10): feedback input. connect to the 0.8v feedback pin of a compatible regulator or the eain pin of the ltc1929 or ltc1629. block diagra w 1706-85 bd 40k vid2 v cc 40k vid3 v cc 40k vid1 v cc 40k vid0 v cc 40k vid25 v cc r fb2 r fb1 10k sense fb gnd v cc 1 2 3 4 6 5 10 9 7 switch control logic
ltc1706-85 5 170685f operatio u the ltc1706-85 is a precision programmable resistive divider designed specifically for use with an entire family of linear technology corporation dc/dc switching regu- lators with 0.8v internal reference and feedback voltages. the ltc1706-85 programs an output voltage ranging from 1.050v to 1.825v in 25mv steps, depending on the state of the vid input pins. the ltc1706-85 in conjunc- tion with a linear technology dc/dc switching regulator can be used to create a high performance voltage regu- lator meeting all the requirements of the intel vrm 8.5 specification. voltage sensing and feedback pins the ltc1706-85 operates by closing the loop between the output node and the feedback node of the regulator with an appropriate resistive divider network. the top feedback resistor, r fb1 , connected between sense and fb, is a fixed value of typically 10k. the bottom feedback resistor, r fb2 , is set by the five vid inputs to generate the desired regulator output voltage. feedback resistors r fb1 and r fb2 are matched and temperature stable in order to provide a highly accurate output voltage. the fb pin is a sensitive node in the circuit. care should be taken to minimize the layout distance between the ltc1706-85 fb node and the regulator feedback node. in addition, it is important to keep tight ground connections between the two chips. vid inputs the desired output voltage is obtained by applying the proper voltage or float condition to the five digital vid inputs. table 1 shows the translation table with each in- put state and the corresponding regulator output voltage. this translation is derived from and adheres to the intel vrm 8.5 specification. each vid input is pulled up by a 40k resistor in series with a diode connected to v cc . to produce a digital low a vid input should be grounded or driven to a low state. the vid inputs must be driven with a maximum v il of 0.8v (v cc = 3.3v). when a vid input is grounded or pulled low with a logic gate, the power supply current will increase because of the resistor from v cc through the series diode to the input. this increase in current is calculated from: i q = n ? (v cc C v diode )/r pullup where n is the number of grounded vid inputs. with typical values of v cc = 3.3v, v diode = 0.6v and r pullup = 40k, each grounded v in input will sink approximately 68 m a. to apply a digital high state the input can be either floated, connected to v cc or driven by a logic gate. the vid inputs should be driven with a minimum v ih of 2v (v cc = 3.3v). because of the diode between v cc and the pull-up resis- tor, the maximum v ih is not limited to v cc . the vid inputs can be driven higher than v cc without being clamped or damaged. this allows the ltc1706-85 to be fully logic compatible and operational over a wide input voltage range, up to the 7v absolute maximum rating. when used with the ltc1629 and ltc1929, the ltc1706-85s fb, sense, v cc and gnd pins should be connected respectively to the eain, v diffout , intv cc and sgnd pins of the ltc1629 and ltc1929. the result of this application is a precisely controlled, multiphase, variable output voltage supply applicable to any low output voltage system such as a personal computer, workstation or network server. in addition to the ltc1629 and ltc1929, the ltc1706-85 also programs a whole family of ltc dc/dc converters that have an onboard 0.8v reference. the ltc1628, ltc1735 and ltc1622 are just a few of the high efficiency step-down switching regulators that will work equally well with the ltc1706-85. contact ltc marketing for a more complete listing of compatible dc/dc regulators.
ltc1706-85 6 170685f table 1. vid inputs and corresponding output voltage code vid3 vid2 vid1 vid0 vid25 voltage 00000 gnd gnd gnd gnd gnd 1.250 00001 gnd gnd gnd gnd float 1.275 00010 gnd gnd gnd float gnd 1.200 00011 gnd gnd gnd float float 1.225 00100 gnd gnd float gnd gnd 1.150 00101 gnd gnd float gnd float 1.175 00110 gnd gnd float float gnd 1.100 00111 gnd gnd float float float 1.125 01000 gnd float gnd gnd gnd 1.050 01001 gnd float gnd gnd float 1.075 01010 gnd float gnd float gnd 1.800 01011 gnd float gnd float float 1.825 01100 gnd float float gnd gnd 1.750 01101 gnd float float gnd float 1.775 01110 gnd float float float gnd 1.700 01111 gnd float float float float 1.725 operatio u code vid3 vid2 vid1 vid0 vid25 voltage 10000 float gnd gnd gnd gnd 1.650 10001 float gnd gnd gnd float 1.675 10010 float gnd gnd float gnd 1.600 10011 float gnd gnd float float 1.625 10100 float gnd float gnd gnd 1.550 10101 float gnd float gnd float 1.575 10110 float gnd float float gnd 1.500 10111 float gnd float float float 1.525 11000 float float gnd gnd gnd 1.450 11001 float float gnd gnd float 1.475 11010 float float gnd float gnd 1.400 11011 float float gnd float float 1.425 11100 float float float gnd gnd 1.350 11101 float float float gnd float 1.375 11110 float float float float gnd 1.300 11111 float float float float float 1.325 typical applicatio s u 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 v out 1.05v to 1.825v 30a vid25 vid0 vid1 vid2 vid3 1 2 3 4 7 v cc ltc1706-85 gnd 9 5 10 6 fb sense from p m6 m5 m4 m1 10 m2 m3 gnd 150 f, 16v 2 5 180 f 4v d2 mbrs 340t3 d1 mbrs 340t3 l1 l2 0.003 0.003 0.47 f 5v ltc1929 0.47 f 0.33 f 0.33 f optional sync clock in 10k 10 10 24k 75k 10 10 3300pf 100pf 1000pf 1000pf 1 f 6.3v 22 f 6.3v 1 f 16v 100pf + + + d7 d8 v in : 12v v out : 1.05v to 1.825, 30a m1 to m6: fds7760a l1 to l2: 1 h sumida cep125-iromc-h d7 to d10: central cmdsh-3tr c out : panasonic eefueog181r 4 3 2 1 4 3 2 1 nc tg1 sw1 boost1 v in bg1 extv cc intv cc pgnd bg2 boost2 sw2 tg2 ampmd run/ss sense1 + sense1 eain pllfltr pllin nc i th sgnd v diffout v os v os + sense2 sense2 + v in 12v 30a, 2-phase vid controlled power supply
ltc1706-85 7 170685f vid controlled high current 70a 4-phase power supply 1706-85 ta03 run/ss sense1 + sense1 eain pllfltr pllin nc i th sgnd v diffout v os v os + sense2 sense2 + run/ss sense1 + sense1 eain pllfltr pllin phasmd i th sgnd v diffout v os v os + sense2 sense2 + clkout tg1 sw1 boost1 v in bg1 extv cc intv cc pgnd bg2 boost2 sw2 tg2 ampmd 1 2 3 4 5 6 7 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 28 27 26 25 24 23 22 21 20 19 18 17 16 15 1 2 3 4 5 6 7 9 10 11 12 13 14 v in 12v v out 1.05v to 1.825v 70a vid25 vid0 vid1 vid2 vid3 1 2 3 4 7 v cc ltc1706-85 gnd 9 5 10 6 100pf v in : 12v v out : 1.05v to 1.825, 70a m1 to m12: si7440dp l1 to l4: 1 h sumida cep125-iromc-h d7 to d10: central cmdsh-3tr c out : kemet t510x477m006as fb sense from p nc tg1 sw1 boost1 v in bg1 extv cc intv cc pgnd bg2 boost2 sw2 tg2 ampmd 10 m7 m10 m11 m8 m9 m6 m5 m4 m1 10 m2 m3 gnd 150 f, 16v 2 gnd 150 f, 16v 2 3 470 f, 6.3v kemet cap 3 470 f, 6.3v kemet cap d3 mbrs 340t3 d2 mbrs 340t3 d1 mbrs 340t3 m12 l4 l1 l2 l3 0.002 0.002 0.002 d4 mbrs 340t3 0.47 f 0.47 f 5v 5v ltc1629 ltc1629 0.47 f 0.33 f 0.33 f optional sync clock in 0.01 f 10k 10 10 24k 10 10 10 10 10k 47pf 75k 100pf 3300pf 1000pf 1000pf 1000pf 1000pf 100pf 0.47 f 1 f 6.3v 1 f 6.3v 22 f 6.3v 22 f 6.3v 1 f 16v 1nf 8 10 10 1 f + + + + + + d9 d10 d7 d8 8 4 3 2 1 4 3 2 1 4 3 2 1 4 3 2 1 0.002 v os v os + v os v os + v diffout typical applicatio s u information furnished by linear technology corporation is believed to be accurate and reliable. however, no responsibility is assumed for its use. linear technology corporation makes no represen- tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
ltc1706-85 8 170685f linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 l fax: (408) 434-0507 l www.linear.com ? linear technology corporation 2001 lt/tp 1202 2k ? printed in usa related parts part number description comments ltc1622 sychnronizable low voltage step-down controller 8-pin msop, 2v v in 10v, 550khz, burst mode ? operation ltc1628/ltc1628-pg dual high efficiency, 2-phase sync step-down controller constant freq, standby, 5v and 3.3v ldos, 3.5v v in 36v ltc1629/ltc1629-pg polyphase ? high efficiency step-down dc/dc controller expandable up to 12 phases, up to 200a, remote sense diff amp ltc1702/ltc1703 dual high efficiency, 2-phase sync step-down controller 550khz, 25mhz gbw, no r sense tm , 2.7v v in 7v ltc1706-81/ltc1706-82 vid voltage programmer with desktop code vrm 8.2-vrm 8.4, v out range: 1.3v to 3.5v ltc1709/ltc1709-8 2-phase sync step-down controller with 5-bit desktop vid 4v v in 36v, pll, 36-pin ssop, current mode operation lt1709-85 2-phase, 5-bit vid, current mode high efficiency 4v v in 36v, 36-pin ssop vrm 8.5 compatiable synchronous step-down switching regulator ltc1735 high efficiency sync step-down controller burst mode operation, 16-pin narrow ssop, fault protection, 3.5v v in 36v ltc1736 high efficiency sync buck controller with 5-bit mobile vid gn-24, power good, output fault protection, 3.5v v in 36v ltc1772 sot-23 low voltage step-down controller 6-pin sot-23, 2.5v v in 10v, 550khz, burst mode operation ltc1773 synchronous step-down dc/dc controller up to 95% efficiency, 550khz operation, 2.65v v in 8.5v, 0.8 v out v in ltc1778 wide operating range step-down controller no r sense , v in up to 36v, current mode power good ltc1929/ltc1929-pg 2-phase sync step-down controller current mode operation, i out up to 40a, 3.5v v in 36v ltc3728 550khz, 2-phase dual output synchronous synchronizable, current mode, 3.5v v in 36v, step-down controller i out up to 25a ltc3729 550khz, polyphase, high efficiency synchronous current mode, 4v v in 36v, 28-lead ssop package step-down switching regulator burst mode and polyphase are registered trademarks of linear technology corporation. no r sense is a trademark of linear technology corporation. package descriptio u ms package 10-lead plastic msop (reference ltc dwg # 05-08-1661) msop (ms) 1001 0.53 0.01 (.021 .006) seating plane 0.18 (.007) 1.10 (.043) max 0.17 0.27 (.007 ?.011) 0.13 0.05 (.005 .002) 0.86 (.034) ref 0.50 (.0197) typ 12 3 45 4.88 0.10 (.192 .004) 0.497 0.076 (.0196 .003) ref 8 9 10 7 6 3.00 0.102 (.118 .004) (note 3) 3.00 0.102 (.118 .004) note 4 note: 1. dimensions in millimeter/(inch) 2. drawing not to scale 3. dimension does not include mold flash, protrusions or gate burrs. mold flash, protrusions or gate burrs shall not exceed 0.152mm (.006") per side 4. dimension does not include interlead flash or protrusions. interlead flash or protrusions shall not exceed 0.152mm (.006") per side 5. lead coplanarity (bottom of leads after forming) shall be 0.102mm (.004") max 0.254 (.010) 0 ?6 typ detail ? detail ? gauge plane 5.23 (.206) min 3.2 ?3.45 (.126 ?.136) 0.889 0.127 (.035 .005) recommended solder pad layout 3.05 0.38 (.0120 .0015) typ 0.50 (.0197) bsc
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