A B C D E Place on edge of board R1 OPT R12 R13 R14 OPT OPT TP7 10 11 33 VSNSOUT2 VSNSOUT3 VSNSOUT4 VSNSOUT1 TP8 R106 R107 R108 OPT OPT OPT 34 CIN3 CIN4 22uF 25V 1210 2 1 PWM ZCD# 32 4 3 VCC AGND AGND 6 5 BOOT PVCC VIN PGND 13 PGND 14 PGND 15 PGND 16 SW VSNSOUT4 RUN4 2 1 ZCD# PWM 3 VCC 4 32 AGND AGND 5 BOOT 6 NC 27 VIN 24 SW C41 OPT VOS2+ COUT6 COUT7 100uF 6.3V 1206 R56 0 + COUT8 COUT9 COUT10 330uF 2.5V R32 OPT 2512 R64 10K 12 13 2 1 PWM ZCD# 3 VCC 32 4 PVCC VIN PGND PGND GL PGND GL U4 FDMF5820DC PGND PGND RUN4 BOOT VIN PGND 14 R66 OPT TMON VOS2- 30 29 28 35 27 2 C27 2.2uF 16V 26 24 SW R70 24.9K VOS3+ C42 OPT L3 COUT11 COUT12 100uF 6.3V 1206 R73 0 E15 R71 10 VOUT3 0.25uH 744301025 R72 3.57K 1% 25 SW R75 + R33 OPT 2512 1 R37 OPT 2512 COUT13 COUT14 COUT15 330uF 2.5V VOS3+ J7 C28 10uF 0805 E16 R79 0 VOS3- VOS3- VOS4+ C31 0.22uF R81 10k 1% R77 10 VOUT4 C30 2.2uF 16V R80 10K PGND -C A PWM 2 3 VCC ZCD# 32 5 4 BOOT AGND 6 NC AGND SW SW PGND SW SW 1.2V/60A GL U5 FDMF5820DC PGND 16 1.8V/60A PGND 23 15 -B GL 22 14 PGND PGND SW 13 VIN 21 12 SW 1.8V/30A 1.5V/30A 1.2V/30A 1.0V/30A 34 SW CIN9 CIN10 22uF 25V 1210 VOUT4 PVCC 20 VOUT3 TMON VIN 19 -A VOUT2 VIN SW 33 VOUT1 EN/FAULT# 18 11 SW 10 VIN 17 9 PHASE VIN 7 + R82 OPT SW R84 10K 30 28 35 27 26 25 24 C34 2.2uF 16V COUT18 COUT19 COUT20 330uF 2.5V R85 10 C43 OPT R86 24.9K CUSTOMER NOTICE 0.25uH 744301025 R87 3.57K 1% R88 0 COUT16 COUT17 100uF 6.3V 1206 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. J9 VOUT4+ 1.0V / 30A VOUT4- D E20 1 VOS4- 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 APPROVALS PCB DES. APP ENG. TECHNOLOGY HZ MIKE S. TITLE: SCHEMATIC SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. C C33 10uF 0805 VOS4- L4 1.2V/120A B VOS4+ E18 J10 31 29 VOUT3+ 1.2V / 30A VOUT3- J8 R74 10 0 FB4 E19 VOUT2- J6 R67 10K C29 OPT R83 100K VOUT2+ 1.5V / 30A R36 OPT 2512 TRK/SS4 R76 J5 31 SW SW 34 15 RUN3 VOS2+ C12 10uF 0805 E12 23 33 CIN7 CIN8 22uF 25V 1210 R3-4 332 E11 R53 10 VOUT2 1 EN/FAULT# SW 43.2K Murata GRM31CR60J107M (100uF, 6.3V, X5R, 1206) L1-4: Wurth 744301025 (0.25uH, DCR=0.325mOhms +/-7%) 0.25uH 744301025 R55 3.57K 1% 25 VIN 22 R69 11 AGND 9 10 ILIM4 COUT1,2,6,7,11,12,16,17: R49 10K L2 26 23 SW 22 SW SW 21 20 SW 19 SW 18 SW SW 16 OPT 5VBIAS PGOOD4 35 SW C21 2.2uF 16V AGND C24 0.22uF IAVG4 C26 VOS1- COUT3-5,8-10,13-15,18-20: Panaasonic EEFSX0E331ER (330uF, 2.5V, 9mOhms) R52 24.9K C10 2.2uF 16V 28 C22 0.22uF R1-4 10.0K 3.3nF 0 C23 0.22uF SW 30 R62 SW 32 OPT 43.2K OPT SW 33 31 VOUT1- VOS2- 21 34 VOUT1+ 1.8V / 30A 3 29 SW R59 20 35 TRK/SS3 C19 R61 ILIM3 IAVG3 C20 J3 J4 R35 OPT 2512 0 5 36 VOS1+ C5 10uF 0805 R58 10 R60 Sanyo 16SVP180MX (180uF, 30mOhms, 3.02A, 16V) 30 SW OPT 43.2K OPT OPT NC 37 PGND 6 38 U3 FDMF5820DC PGND SW IAVG4 39 GL PHASE ISNS4P C3-4 7 8 VSNSN4 40 PGND PGND 14 15 C14 0.22uF C15 IAVG2 R57 ILIM2 C16 TRK/SS2 C17 PHASE VIN ISNS4N 41 13 VINVIN- 31 GL 7 50 49 PWM2 PGOOD1 52 51 RUN2 ISNS3N VSNSOUT4 42 C13 0.22uF 12 R48 OPT PGND 8 JP4 53 ISNS3P VSNSOUT3 C2-4 2 C32 OPT RUN1 VSNSN3 100pF C1-4 R2-4 3.32K 3.3nF R78 18.2K PWM1 IAVG3 44 43 43.2K OPT COMP4 RB-4 VOS415.0K VIN CLKOUT VSNSP3 VSNSP4 R31 OPT 2512 R45 10K PVCC SW 3 RT-4 10.0K 56 ILIM3 RB-3 VOS310k TRK/SS4 RUN4 OFF RT-3 10.0K 55 TRACK/SS3 COMP3 45 R51 C11 VIN+ 7V - 14V VOS1- C7 2.2uF 16V 19 VOS4+ E17 COUT3 COUT4 COUT5 330uF 2.5V E8 PGND SW 19 FB3 SGND VOS3+ E14 1 + 1 EN/FAULT# 18 18 PGOOD2 59 R68 100K ON COUT1 COUT2 100uF 6.3V 1206 R34 0 R38 3.57K 1% VIN 8 17 5VBIAS TRACK/SS4 24 TMON VIN R2-3 3.48K 16 C2-3 100pF VCC 2 PGOOD3 0.25uH 744301025 25 E6 R29 10 VOUT1 L1 26 SW VIN 16 C1-3 3.3nF VINSNS 47 46 ILIM1 IAVG1 34 CIN5 CIN6 22uF 25V 1210 ILIM4 VSNSOUT3 C3-3 3.3nF R1-3 10.0K TRACK/SS2 FB2 PGOOD3 R3-3 332 R65 10k 1% 15 COMP2 48 29 RUN3 ILIM2 28 13 IAVG2 VSNSP2 RUN3 12 VSNSN2 27 11 FB3 COMP3 C1-2 2.2nF 9 10 ISNS2P PWM3 JP3 COMP2 FB2 14 2 C25 OPT C18 1uF 8 ISNS1N VSNSOUT2 PGOOD4 3 C2-2 100pF 7 IAVG1 ISNS2N PWM4 OFF R2-2 4.75K VOS2- ILIM1 ISNS1P 26 ON R3-2 332 R63 18.2K RUN3 1 27 SW VIN 33 SGND 25 VIN R1-2 10.0K RB-2 10k VSNSOUT1 RUN4 E13 C3-2 3.3nF RT-2 15.0K 6 TRACK/SS4 VOS2+ 5 VIN 11 U1 LTC7851EUHH VSNSN1 24 TRK/SS3 4 VSNSP1 20 TRACK/SS3 3 VCC 1 VSNSOUT2 2 RB-1 VOS110.0K 23 R54 RT-1 20.0K COMP1 22 VOS1+ 5VBIAS 1 COMP4 COMP1 FREQ FB1 E10 54 RUN1 RUN2 CLKIN 100pF 9 10 SW 2.2nF C2-1 R50 100K 17 5.62K 58 PGOOD2 35 R47 0 C1-1 R2-1 5VBIAS 3 0 C8 0.22uF TRK/SS1 57 JP2 R46 10k 1% TRACK/SS1 C9 OPT FB4 3 2 R44 30.9K J1 CIN2 180uF 16V VIN+ VOS1+ 0 R42 C6 OPT 21 OFF C3-1 R3-1 332 3.3nF R1-1 10.0K RUN2 R41 Fsw = 400kHz FB1 17 R43 18.2K RUN2 1 VSNSOUT1 10-21-15 CIN3-10: Murata GRM32ER71E226K (22uF, 16V, X5R, 1210) C40 OPT R28 24.9K C4 2.2uF 16V 28 R39 10 VIN ON 30 GL R40 + E5 CIN1,2: 29 GL U2 FDMF5820DC CIN1 180uF 16V J2 TRK/SS2 E9 1 NC TMON PGND DATE Mike S. 4 VIN PGND 12 E3 R11 10K 31 EN/FAULT# VIN E7 TRACK/SS2 7 VIN SW OPT 9 R9 OPT 23 OPT TRK/SS4 R27 IAVG4 OPT TP6 TRK/SS3 R26 + 1 PGOOD1 TP5 R30 100K OPT IAVG3 TRK/SS2 R25 R7 10K SW 5VBIAS OPT IAVG2 ILIM4 R24 22 OPT IAVG1 ILIM3 R23 SW JP1 ILIM2 TRK/SS1 21 C3 OPT R18 OPT R22 FB3 FB4 R21 OPT R20 10k 1% R17 OPT 20 R19 OPT 2 R16 OPT SW OFF 3 RUN1 R6 OPT 19 ON 1 R5 OPT C1 2.2uF 16V C2 0.22uF SW R15 18.2K RUN1 R4 OPT ILIM1 4 RUN4 18 FB2 R10 OPT VIN RUN3 8 FB1 RUN2 VIN E4 OPT RUN1 COMP4 PHASE R8 COMP3 0 SW VCC TRK/SS1 COMP2 R3 SW COMP1 TRACK/SS1 VIN Components to parallel two or more phases APPROVED PRODUCTION 1 0 17 Place these components on edge of board DESCRIPTION 2 5VBIAS R2 REVISION HISTORY REV __ CLKOUT E2 SW CLKIN E1 ECO DATE: LTC Confidential-For Customer Use Only HIGH OUTPUT CURRENT 4 PHASE STEP-DOWN CONVERTER LTC7851EUHH DEMO CIRCUIT 2380A-A IC NO. N/A SCALE = NONE www.linear.com Fax: (408)434-0507 Wednesday, January 27, 2016 E SHEET 1 REV. 2 OF 2 A B C D E 4 4 DYNAMIC LOAD CIRCUIT FOR VOUT1 AND VOUT2 TO-263 = D2PAK VOUT1 E22 OPT PULSE GEN A R93 10k 1% E24 GND VIN 3 VOUT2 C37 2.2uF 16V J12 VOUT2 VOUT3 R101 0 mOhm 2512 E25 OPT PULSE GEN B R103 10k 1% E26 GND VIN SW PG BOOST EN BD GND FB GND RT 6 C35 0.1uF 1 OFF 3 5VBIAS R91 C39 22pF C36 10uF 6.3V 0805 0 1206 C38 10uF 6.3V 0805 8 E21 5V / 350mA E23 GND 1 R94 316K 10 R98 226K 11 ON R92 1.0M 7 GND 3 R99 OPT 2 JP5 R100 OPT J14 VOUT3 VOUT4 J15 R102 OPT 2512 VOUT4 E28 R104 0.002 1% 2512 2 5 R97 100K DYNAMIC LOAD CIRCUIT FOR VOUT3 AND VOUT4 Q3 SUM60N02-3m9P TO-263 TO-263AB 2 5VBIAS ISTEPA+ 2mV / Amp 5% DUTY CYCLE MAX. E29 ISTEPA5VBIAS TO-263 = D2PAK 9 4 E27 R95 0.002 1% 2512 3 VOUT1 R90 OPT 2512 L5 22uH CDRH4D22/HPNP-220MC U6 LT3970EMS J11 R89 0 mOhm 2512 Q1 SUM60N02-3m9P TO-263AB BIAS SUPPLY FOR DrMOS and LTC7851 ISTEPB+ 2mV / Amp 5% DUTY CYCLE MAX. E30 ISTEPB- VOUT2 VOUT1 + COUT23 COUT22 COUT21 OPT 7343-D15T + VOUT3 COUT28 COUT29 COUT27 OPT 7343-D15T + VOUT4 COUT34 COUT35 COUT33 OPT 7343-D15T + COUT39 COUT41 COUT40 OPT 7343-D15T 2 1 1 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. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 APPROVALS PCB DES. APP ENG. TECHNOLOGY HZ MIKE S. TITLE: SCHEMATIC SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. A B C D N/A SCALE = NONE DATE: IC NO. www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only HIGH OUTPUT CURRENT 4 PHASE STEP-DOWN CONVERTER LTC7851EUHH DEMO CIRCUIT 2380A-A Tuesday, January 26, 2016 SHEET 2 E REV. 2 OF 2