1 description lt c7150sey high efficiency 20a synchronous buck regulator demonstration circuit 2411a is a high efficiency synchro - nous buck regulator with a 3.1v to 20v input range. it can supply 20a maximum load current at 1.2v output. the demo board features the lt c ? 7150s regulator. no external mosfets nor external current sense resistor are required. it uses a phase-lockable controlled on-time con - stant-frequency, current mode architecture, ideal for high step-down ratio applications. the operating frequency is programmable from 400khz to 3mhz with an external resistor (r5). the ltc7150s is housed in a 6mm 5mm 1.3mm 42-lead bga package. the light load operation mode of the converter is deter - mined with the mode/sync pin. use the jp3 jumper to select discontinuous mode (dcm), forced continuous mode (ccm), or to synchronize to an external clock. l , lt, ltc, ltm, linear technology and the linear logo are registered trademarks of analog?devices, inc. all other trademarks are the property of their respective owners. performance summary multiple ltc7150 s regulators can be paralleled for mul - tiphase operation to provide more than 20a of current ( jp2 : 1- ph, for standard single phase operation). to shut down the converter, one simple way is to force the run pin below 1.15v ( jp1: off). the power good output (pgood terminal) is low when the output voltage is outside of the 7.5% regulation window. the ltc7150 s data sheet gives a complete description of the operation and application information. the data sheet must be read in conjunction with this demo manual. design files for this circuit board are available at http://www.linear.com/demo/dc2411a specifications are at t a = 25c parameter condition value input voltage range 3.1v to 20v output voltage v in = 3.1v to 20v, i out = 0a to 20a 1.2v 2% maximum output current v in = 3.1v to 20v, v out = 1.2v 20a typical switching frequency 400khz typical efficiency v in = 12v, i out = 20a 88.5% typical output voltage ripple v in = 12v, i out = 20a 25mv p-p dc2411af demo manual dc2411a
2 quick start procedure figure 1. proper measurement equipment setup demonstration circuit 2411a is easy to set up to evaluate the performance of the ltc7150s. 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 (3.1v to 20v) and gnd (input return). 2. connect the 1.2v 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 1.2v 2%. 5. once the proper output voltages are established, adjust 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 rip - ple, 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 probe s ground ring needs to touch the (C ) lead and the probe tip needs to touch the (+) lead. dc2411af demo manual dc2411a
3 quick start procedure figure 2. measuring output voltage ripple + ? v out gnd c out figure 3. efficiency vs load current (v o = 1.2v, 400khz) dc2411af demo manual dc2411a 3.3v in dcm 10 12 14 16 18 20 75 80 85 90 5v in dcm 95 100 efficiency (%) dc2411a f03 12v in dcm load current (a) 0 2 4 6 8
4 quick start procedure figure 4. thermal picture (v in = 12v, i o = 20a. 21c ambient, no forced airflow) dc2411af demo manual dc2411a
5 quick start procedure figure 5. load step transient test (v in = 12v, total i o : 10a to/from 20a) v o 50mv/div ac-coupled 10a load step 5a/div dc2411af demo manual dc2411a
6 parts list item qty reference part description manufacturer/part number required circuit components 1 1 cin1 cap, alum elec 180f 20% 25v panasonic., 25svpf180m 2 1 cithp1 cap, 0603 22pf 5% 50v cog avx, 06035a220jat2a 3 1 cith1 cap, 0603 2200pf 5% 50v cog avx, 06035a222jat2a 4 2 cout1, cout3 cap, 1206 100f 20% 6.3v x5r avx, 12066d107mat2a 5 2 cout2, cout4 cap, 7343, 470f, 2.5v, sp-cap panasonic, eefgx0e471r 6 2 c2, c4 cap, 1210 22f 20% 25v x5r avx, 12103d226mat2a 7 1 c6 cap, 0603 4.7f 20% 6.3v x5r avx, 06036d475kat2a 8 2 c7, c8 cap, 0603 0.1f 10% 25v x5r avx, 06033d104kat2a 9 2 c11, c13 cap, 0805 10f 20% 25v x5r avx, 08053d106mat2a 10 1 l1 ind, 0.33h wurth elektronik, 744308033 11 3 rfb1, r7, r20 res, 0603 10k 1% vishay, crcw060310k0fkea 12 1 rith1 res, 0603 4.22k 1% vishay, crcw06034k22fkea 13 1 r1 res, 0603 10? 5% 1/10w vishay, crcw060310r0jnea 14 1 r6 res, 0603 1? 5% 1/10w vishay, crcw06031r00jnea 15 2 r2, r4 res, 0603 100k 1% 1/10w vishay, crcw0603100kfkea 16 1 r5 res, 0603 422k 1% 1/10w vishay, crcw0603422kfkea 17 1 u1 ic, LTC7150SEY#pbf linear tech., LTC7150SEY#pbf additional demo board circuit components 1 0 c5, c9, c10, cout6, cout7 opt 2 0 c12 cap, 0805 4.7f 20% 6.3v x5r avx, 08056d475kat2a 3 0 r22 res, 2512 0.01? 1% 1/2w vishay, wsl2512r0100fea 4 0 q5 xstr, mosfet, dpak-to252aa vishay, sud50n03-12p-e3 hardware for demo board only 1 11 e1-e10, e12 testpoint, turret, 0.094" pbf mill-max, 2501-2-00-80-00-00-07-0 2 1 jp1 header, 3-pin 0.079 single row wurth elektronik, 62000311121 3 1 jp2 header, double row header, 2 3 pin wurth elektronik, 62000621121 4 1 jp3 header, double row header, 2 2 pin wurth elektronik, 62000421121 5 4 j1-j4 jack, banana keystone, 575-4 6 3 jp1-jp3 shunt, 0.079" center wurth elektronik, 60800213421 7 4 mh1-mh4 standoff, nylon, 0.5, 1/2" wurth elektronik, 702935000 8 1 fab printed circuit board demo circuit 2411a 9 1 stencil (top ) stencil dc2411a dc2411af demo manual dc2411a
7 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 1 1 2 2 a a b b on off run 3.1v - 20v 1.2v 3-ph 1-ph 2-ph 25v 25v ccm/sync dcm 6.3v 6.3v 6.3v 744308033 25v 1% 25v load step circuit 20a max 1% vin intvcc vin intvcc vout vout revision history description date approved eco rev 12-12-16 production 3 charlie __ revision history description date approved eco rev 12-12-16 production 3 charlie __ revision history description date approved eco rev 12-12-16 production 3 charlie __ size date: ic no. rev sheet of title: contract no. approvals pcb des. 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. 3 1 7102 ,02 yraunaj ,yadirf 1 high efficiency 20a synchronous buck regulator hz charlie dc2411a size date: ic no. rev sheet of title: contract no. approvals pcb des. 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. 3 1 7102 ,02 yraunaj ,yadirf 1 high efficiency 20a synchronous buck regulator hz charlie dc2411a size date: ic no. rev sheet of title: contract no. approvals pcb des. 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. 3 1 7102 ,02 yraunaj ,yadirf 1 high efficiency 20a synchronous buck regulator hz charlie LTC7150SEY dc2411a c13 10uf c8 0.1uf e5 pgood j1 vin + cout2 470uf 2.5v q5 sud50n03-12p 3 1 2 e10 pulse gen j4 gnd r2 100k c5 opt e9 clkout cout1 100uf 1206 c4 22uf 1210 e4 gnd e2 vin r4 100k c11 0805 jp2 phmode 1 3 5 2 4 6 c2 22uf 1210 r20 10k + cout4 470uf 7343 j3 gnd c9 opt cout6 1206 opt e3 gnd sense e1 vo sense u1 LTC7150SEY pvin c2 run b2 sw d3 mode/sync b3 pgnd e5 phmode a1 rt a3 pvin c5 pvin c6 pvin d1 track/ss b4 clkout b1 intvcc b6 ith a4 sgnd b5 pgnd e1 pgnd e2 pgnd e6 pgnd f1 pgnd f2 pgood a2 vout- a6 fb a5 sw d4 sw c4 sw e3 sw c3 sw e4 sw f3 sw f4 sw g3 sw g4 svin c1 pvin d2 pvin d5 pvin d6 pgnd f5 pgnd f6 pgnd g1 pgnd g2 pgnd g5 pgnd g6 r1 10 j2 vout jp1 1 2 3 e12 load step c10 opt e7 track c12 4.7uf 0805 c6 4.7uf jp3 m/s 1 3 2 4 e8 gnd + cout8 opt rith1 4.22k r7 10k cithp1 22pf l1 0.33uh + cin1 180uf 25v cout7 1206 opt cout3 100uf 1206 r5 422k c7 0.1uf rfb1 10k e6 sync cith1 2.2nf + cout5 opt r22 0.01 2512 r6 1 dc2411af demo manual dc2411a
8 ? linear technology corporation 2017 lt 0717 ? 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 european union directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other 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 from 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 compliant or agency certified (fcc, ul, ce, etc.). no license is granted under any patent right or other intellectual property whatsoeve r. 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 application engineer. mailing address: linear technology 1630 mccarthy blvd. milpitas, ca 95035 copyright ? 2004, linear technology corporation dc2411af demo manual dc2411a
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