1 dc1700af demo manual dc1700a description LTC3613EWKH fast, high efficiency step-down regulator demonstration circuit 1700a is a fast, high efficiency synchronous buck dc/dc converter with 4.5v to 24v input range. it can supply 15a maximum load current at 1.5v output. the demo board features the ltc ? 3613ewkh regulator. no external mosfets are required. the con- trolled on-time constant frequency valley current mode architecture allows for both fast transient response and constant frequency switching in steady-state operation. differential output voltage sensing along with a precision internal reference combine to offer an accurate output regulation. the ltc3613 is ideal for applications such as distributed power systems, servers and point-of-load converters. the LTC3613EWKH is in a 7mm 9mm 54-pin qfn package. l , lt, ltc, ltm, linear technology and the linear logo are registered trademarks of linear technology corporation. all other trademarks are the property of their respective owners. performance summary the light load operation mode of the converter is de- termined with the mode/pllin pin. use jp2 jumper to select discontinuous mode (dcm) or forced continuous mode (ccm) operation. switching frequency is pre-set at about 350khz. this frequency can be modified from 200khz to 1mhz by changing the value of a resistor (r18). the converter can also be externally synchronized from 200khz to 1mhz through the mode/pllin pin (pllin terminal on the board). to shut down the converter, one simple way is to force the run pin below 1.1v (jp1: off). the power good output (pgood terminal) is low when the output voltage is outside of the 7.5% regulation window. design files for this circuit board are available at http://www.linear.com/demo (t a = 25c) parameter conditions value input voltage range 4.5v to 24v output voltage, v out v in = 4.5v to 24v, i out = 0a to 15a 1.5v 2% maximum output current, i out v in = 4.5v to 24v, v out = 1.5v 15a typical output ripple v in = 12v, i out = 15a (20mhz bw) 40mv pCp typical efficiency v in = 12v, v out = 1.5v, i out = 15a 87.5% typical switching frequency 350khz
2 dc1700af demo manual dc1700a quick start procedure figure 1. proper measurement equipment setup figure 2. measuring output voltage ripple demonstration circuit 1700a is easy to set up to evaluate the performance of the ltc3613. refer to figure 1 for the proper measurement equipment setup and follow the procedure below: 1. with power off, connect the input power supply to v in (4.5v to 24v) and gnd (input return). 2. connect the 1.5v output load between v out and gnd (initial load: no load). 3. connect the dvms to the input and outputs. 4. turn on the input power supply and check for the proper output voltages. v out should be 1.5v 2%. 5. once the proper output voltages are established, ad- just the loads within the operating range and observe the output voltage regulation, ripple voltage and other parameters. note: when measuring the output or input voltage ripple, do not use the long ground lead on the oscilloscope probe. see figure 2 for the proper scope probe technique. short, stiff leads need to be soldered to the (+) and (C) terminals of an output capacitor. the probes ground ring needs to touch the (C) lead and the probe tip needs to touch the (+) lead. +C v out gnd c out
3 dc1700af demo manual dc1700a quick start procedure figure 3. efficiency vs load current (v in = 12v, v o = 1.5v, ccm) load current (a) 0 82 efficiency (%) 90 89 88 87 86 85 84 83 91 51015
4 dc1700af demo manual dc1700a parts list item qty reference part description manufacturer/part number required circuit components 1 2 cin1, cin2 cap , 1210 10f 10% 16v x5r avx, 1210yd106kat 2 1 cin4 cap , 82f, 25v, sanyo sanyo, 25svpd82m 3 2 cout1, cout2 cap , 1206 100f 20% 6.3v x5r murata, grm31cr60j107me39l 4 2 cout3, cout4 cap , 7343 330f 20% 2.5v poscap sanyo 2r5tpe330m9 5 2 c1, c8 cap , 0603 0.1f 10% 25v x7r tdk c1608x7r1e104k 6 1 c2 cap , 0603 1000pf 10% 50v x7r avx, 06035c102kat 7 2 c3, c5 cap , 0805 4.7f 10% 16v x5r tdk c2012x5r1c475k 8 1 c6 cap , 0603 47pf 10% 25v npo avx, 06033a470kat2a 9 1 c7 cap , 0603 0.01f 10% 50v x7r avx, 06035c103kat 10 1 c9 cap , 0603 270pf 10% 25v npo avx, 06033a271kat2a 11 1 c10 cap , 0603 1f 10% 25v x5r avx, 06033d105kat 12 1 d1 diode,cmdsh-3 sod323 central cmdsh-3 13 1 l1 ind., 0.47h, fp1109 series coiltronics, fp1109-r47-r 14 1 q5 xstr, mosfet, dpak-to252aa vishay sud50n03-12p-e3 15 1 rs1 res, 2010 0.0015 1% 1/2w vishay wsl20101l500fea 16 1 r1 res, 0603 100k 1% 1/10w vishay crcw0603100kfkea 17 3 r2, r12, r17 res, 0603 0 jumper vishay crcw06030000z0ea 18 2 r4, r5 res, 0603 10 1% 1/10w vishay crcw060310r0fkea 19 2 r6, r8 res, 0603 100 1% 1/10w panasonic, erj-3ekf1000v 20 1 r10 res, 0603 90.9k 1% 1/10w panasonic, erj-3ekf9092v 21 1 r11 res, 0603 60.4k 1% 1/10w vishay, crcw060360k4fkea 22 1 r13 res, 0603 2.2 1% 1/10w nic, nrc06f2r20trf 23 1 r15 res, 0603 21k 1% 1/10w vishay, crcw060321k0fkea 24 1 r18 res, 0603 115k 1% 1/10w vishay, crcw0603115kfkea 25 2 r20, r23 res, 0603 10k 1% 1/10w nic, nrc06f1002trf 25 1 r22 res, 2010 0.01 1% 1/2w vishay wsl2010r0100fea 27 1 u1 LTC3613EWKH qfn-56-7x9 additional demo board circuit components 28 1 cin3 opt, 1210 29 2 cout5, cout6 opt 30 3 c4, r9, r16 opt 31 1 r3 opt 32 4 r7, r14, r19, r21 opt demo board only 33 12 e1, e2, e3, e4, e5, e6, e7, e8, turret mill-max 2501-2-00-80-00-00-07-0 34 e9, e10, e11, e12 35 2 jp1, jp2 header, 3pin, 2mm samtec tmm-103-02-l-s 36 2 xjp1, xjp2 shunt, 2mm samtec 2sn-bk-g 37 2 j1, j2 jack, banana keystone 575-4 38 2 j3, j4 conn, bnc, 5 pins connex 112404
5 dc1700af demo manual dc1700a 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 representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. schematic diagram 5 5 4 4 3 3 2 2 1 1 d d c c b b a a 1. when dcr sensing is implemented, short rs1 and r9; do not populate r6 and r8. notes: unless otherwise specified 1.5v / 15a load step load step circuit 5% duty cycle max run fsw = 350khz circuit on off 0 opt opt vout ccm mode dcm 2. all resistors are in 0603 all capacitors are in 0603 4.5v - 24v sw sw s+ extvcc vout extvcc vout s+ s- s- intvcc vin intvcc vin intvcc intvcc intvcc vin intvcc revision history description date approved eco rev charlie z. production 3 08-23-11 __ revision history description date approved eco rev charlie z. production 3 08-23-11 __ revision history description date approved eco rev charlie z. production 3 08-23-11 __ size date: ic no. rev. sheet of title: approvals pcb des. app eng. technology fax: (408)434-0507 milpitas, ca 95035 phone: ( 408)432-1900 1630 mccarthy blvd. ltc confidential-for customer use only customer notice linear technology has made a best effort to design a circuit that meets customer-supplied specifications; however, it remains the customer's responsibility to verify proper and reliable operation in the actual application. component substitution and printed circuit board layout may significantly affect circuit performance or reliability. contact linear technology applications engineering for assistance. this circuit is proprietary to linear technology and schematic supplied for use with linear technology parts. scale = none www.linear.com 3 tuesday, august 23, 2011 11 fast, high efficiency step-down regulator ak charlie z. n/a LTC3613EWKH demo circuit 1700a size date: ic no. rev. sheet of title: approvals pcb des. app eng. technology fax: (408)434-0507 milpitas, ca 95035 phone: ( 408)432-1900 1630 mccarthy blvd. ltc confidential-for customer use only customer notice linear technology has made a best effort to design a circuit that meets customer-supplied specifications; however, it remains the customer's responsibility to verify proper and reliable operation in the actual application. component substitution and printed circuit board layout may significantly affect circuit performance or reliability. contact linear technology applications engineering for assistance. this circuit is proprietary to linear technology and schematic supplied for use with linear technology parts. scale = none www.linear.com 3 tuesday, august 23, 2011 11 fast, high efficiency step-down regulator ak charlie z. n/a LTC3613EWKH demo circuit 1700a size date: ic no. rev. sheet of title: approvals pcb des. app eng. technology fax: (408)434-0507 milpitas, ca 95035 phone: ( 408)432-1900 1630 mccarthy blvd. ltc confidential-for customer use only customer notice linear technology has made a best effort to design a circuit that meets customer-supplied specifications; however, it remains the customer's responsibility to verify proper and reliable operation in the actual application. component substitution and printed circuit board layout may significantly affect circuit performance or reliability. contact linear technology applications engineering for assistance. this circuit is proprietary to linear technology and schematic supplied for use with linear technology parts. scale = none www.linear.com 3 tuesday, august 23, 2011 11 fast, high efficiency step-down regulator ak charlie z. n/a LTC3613EWKH demo circuit 1700a r9 r9 c6 47pf c6 47pf e9 extvcc e9 extvcc c10 1uf c10 1uf r3 r3 cin2 10uf 25v 1210 cin2 10uf 25v 1210 r12 0 r12 0 j4 j4 r23 10k r23 10k cin3 1210 opt cin3 1210 opt c1 0.1uf 16v c1 0.1uf 16v cout2 100uf 6.3v 1206 cout2 100uf 6.3v 1206 d1 cmdsh-3 d1 cmdsh-3 1 2 j3 j3 r1 100k r1 100k e3 vin+ e3 vin+ u1b LTC3613EWKH u1b LTC3613EWKH pvin 2 pvin 3 pvin 4 pvin 5 pvin 6 pvin 7 pvin 8 pvin 9 sgnd 16 sgnd 17 sgnd 19 sgnd 28 sgnd 29 pgnd 36 pgnd 37 pgnd 38 pgnd 39 pgnd 40 pgnd 41 pgnd 42 pgnd 43 pgnd 44 sw 45 sw 46 sw 47 sw 48 sw 49 sw 50 sw 51 nc 52 pvin 53 pvin 54 pvin 55 pvin 56 sgnd 57 sw 59 pvin 58 c4 opt c4 opt r8 100 r8 100 e7 pulse gen e7 pulse gen r2 0 r2 0 r14 opt r14 opt r15 21k r15 21k e2 vo_sns- e2 vo_sns- c9 270pf c9 270pf e8 gnd e8 gnd e1 vo_sns+ e1 vo_sns+ + cout3 330uf 7343 2.5v + cout3 330uf 7343 2.5v cout5 1206 opt cout5 1206 opt cin1 10uf 25v 1210 cin1 10uf 25v 1210 e12 track e12 track e4 vin e4 vin r21 opt r21 opt rs1 2010 0.0015 rs1 2010 0.0015 r17 r17 c7 0.01uf c7 0.01uf e5 gnd e5 gnd q5 sud50n03-12p q5 sud50n03-12p 3 1 2 r5 10 r5 10 e11 pgood e11 pgood r13 2.2 r13 2.2 r22 0.01 2010 r22 0.01 2010 jp1 jp1 1 3 2 r10 90.9k r10 90.9k cout6 1206 opt cout6 1206 opt jp2 jp2 1 3 2 u1a LTC3613EWKH u1a LTC3613EWKH pgood 13 sns+ 14 sns- 15 vout 18 vosns- 20 vosns+ 21 track/ss 22 ith 23 vrng 24 rt 25 run 26 extvcc 30 mode/pllin 31 intvcc 33 pgnd 36 nc 27 sw 10 pvin 1 boost 11 svin 32 sgnd 12 intvcc 34 sw 35 l1 0.47uh fp1109-r47 l1 0.47uh fp1109-r47 + cin4 82uf 25v sanyo 25svpd82m + cin4 82uf 25v sanyo 25svpd82m r11 60.4k r11 60.4k e10 pllin e10 pllin c8 0.1uf 50v c8 0.1uf 50v r6 100 r6 100 j1 vout j1 vout + cout4 330uf 7343 2.5v + cout4 330uf 7343 2.5v cout1 100uf 6.3v 1206 cout1 100uf 6.3v 1206 c5 4.7uf 16v 0805 c5 4.7uf 16v 0805 c2 1000pf c2 1000pf e6 vin- e6 vin- j2 gnd j2 gnd r7 opt r7 opt r16 opt r16 opt c3 4.7uf 16v 0805 c3 4.7uf 16v 0805 r4 10 r4 10 r18 115k r18 115k r19 opt r19 opt r20 10k r20 10k
6 dc1700af demo manual dc1700a linear technology corporation 1630 mccarthy blvd., milpitas, ca 95035-7417 (408) 432-1900 fax: (408) 434-0507 www.linear.com ? linear technology corporation 2011 lt 1011 ? printed in usa demonstration board important notice linear technology corporation (ltc) provides the enclosed product(s) under the following as is conditions: this demonstration board (demo board) kit being sold or provided by linear technology is intended for use for engineering development or evaluation purposes only and is not provided by ltc for commercial use. as such, the demo board herein may not be complete in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety measures typically found in finished commercial goods. as a prototype, this product does not fall within the scope of the europ ean union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or ot her regulations. if this evaluation kit does not meet the specifications recited in the demo board manual the kit may be returned within 30 days from the date of delivery for a full refund. the foregoing warranty is the exclusive warranty made by the seller to buyer and is in lieu of all other warranties, expressed, implied, or statutory, including any warranty of merchantability or fitness for any particular purpose. except to the extent of this indemnity, neither party shall be liable to the other for any indirect, special, incidental, or consequential damages. the user assumes all responsibility and liability for proper and safe handling of the goods. further, the user releases ltc fro m all claims arising from the handling or use of the goods. due to the open construction of the product, it is the users responsibility to take any and all appropriate precautions with regard to electrostatic discharge. also be aware that the products herein may not be regulatory co mpliant or agency certified (fcc, ul, ce, etc.). no license is granted under any patent right or other intellectual property whatsoever. ltc assumes no liability for applications assistance, customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind . ltc currently services a variety of customers for products around the world, and therefore this transaction is not exclusive . please read the demo board manual prior to handling the product . persons handling this product must have electronics training and observe good laboratory practice standards. common sense is encouraged . this notice contains important safety information about temperatures and voltages. for further safety concerns, please contact a ltc applica- tion engineer. mailing address: linear technology 1630 mccarthy blvd. milpitas, ca 95035 copyright ? 2004, linear technology corporation
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