A B C D E REVISION HISTORY Place on edge of board CLKOUT E2 5VBIAS R1 0 IAVG2 IAVG3 0 R12 R13 R14 0 0 0 TP6 0 0 TP7 10 11 33 VSNSOUT2 VSNSOUT3 VSNSOUT4 VSNSOUT1 R106 R107 R108 0 0 0 34 CIN3 CIN4 22uF 25V 1210 TP8 2 1 PWM ZCD# 32 3 VCC 4 AGND PGND 13 PGND 14 PGND PGND 16 COUT1 COUT2 100uF 6.3V 1206 R34 0 R38 3.57K 1% + RUN4 C3-4 OPT R3-4 OPT 2 1 ZCD# PWM 3 VCC 4 32 AGND AGND 5 BOOT 6 NC SW 23 SW 22 SW SW 21 20 SW 19 SW 18 SW SW 24 VOS2+ C41 OPT COUT6 COUT7 100uF 6.3V 1206 R56 0 VOS2+ R53 10 VOUT2 + E11 OPT COUT8 COUT9 COUT10 330uF 2.5V 12 13 R32 0 mOhm 2010 2 1 PWM ZCD# 3 VCC 32 4 BOOT AGND AGND VIN PGND PGND GL PGND GL U4 FDMF5820DC PGND 15 R66 OPT PVCC PGND 14 PGND VOS2- R36 0 mOhm 2010 TP3 30 29 28 35 27 2 C27 2.2uF 16V 26 24 SW VOS3+ C42 OPT L3 COUT11 COUT12 100uF 6.3V 1206 R73 0 VOS3+ R71 10 VOUT3 0.25uH 744301025 R72 3.57K 1% 25 SW R70 24.9K + TRK/SS4 C29 OPT R76 R33 0 mOhm 2010 1 R37 0 mOhm 2010 E15 OPT COUT13 COUT14 COUT15 330uF 2.5V VOUT3+ J7 C28 10uF 0805 R79 0 VOS3E16 VOS3- OPT VOS4+ C31 0.22uF R81 OPT 1% R77 10 VOUT4 C30 2.2uF 16V R80 10K PGND PGND -C PWM 2 3 VCC ZCD# 32 5 4 BOOT AGND 6 NC AGND SW SW SW 1.2V/60A GL U5 FDMF5820DC PGND 16 1.8V/60A PGND SW 15 -B GL 23 14 PGND PGND 22 13 VIN SW 12 21 1.8V/30A 1.5V/30A 1.2V/30A 1.0V/30A 34 SW CIN9 CIN10 22uF 25V 1210 VOUT4 SW VOUT3 PVCC 20 -A VOUT2 TMON VIN 19 33 VOUT1 VIN SW 11 R82 OPT EN/FAULT# 18 10 E19 VIN SW 9 17 R83 100K PHASE VIN 7 + 5VBIAS SW R84 10K 28 27 26 25 24 COUT18 COUT19 COUT20 330uF 2.5V C34 2.2uF 16V R86 24.9K R85 OPT C43 OPT CUSTOMER NOTICE L4 0.25uH 744301025 R87 3.57K 1% 1.2V/120A 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. B C D J9 VOUT41 VOS4E20 VOS4- OPT 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 APPROVALS PCB DES. HZ APP ENG. MIKE S. TECHNOLOGY LTC Confidential-For Customer Use Only OUTPUT CURRENT 4 PHASE STEP-DOWN CONVERTER LTC7851EUHH DEMO CIRCUIT 2380A-C IC NO. N/A SCALE = NONE www.linear.com Fax: (408)434-0507 TITLE: SCHEMATIC HIGH SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. A VOUT4+ C33 10uF 0805 J10 30 35 VOS4+ E18 OPT TP4 31 29 VOUT3- J8 R74 OPT 0 FB4 VOUT2- J6 R67 10K 31 SW R75 VOUT2+ J5 C12 10uF 0805 E12 VOS2- OPT R64 10K SW 34 Murata GRM31CR60J107M (100uF, 6.3V, X5R, 1206) COUT1,2,6,7,11,12,16,17: 1 23 33 VOS1- 3 0.25uH 744301025 R55 3.57K 1% 25 TMON SW OPT VOUT1- L1-4: Wurth 744301025 (0.25uH, DCR=0.325mOhms +/-7%) L2 26 VIN 22 OPT C1-4 27 VIN SW R69 11 CIN7 CIN8 22uF 25V 1210 RUN4 35 EN/FAULT# SW ILIM4 RUN3 R2-4 OPT VIN SW 9 10 C2-4 17 16 OPT 21 30 VOUT1+ 1.2V / 120A R49 10K R52 24.9K C10 2.2uF 16V 28 C22 0.22uF C24 0.22uF IAVG4 C26 J3 TP2 29 SW C21 2.2uF 16V 20 32 0 C23 0.22uF 5 33 31 R62 NC 34 OPT OPT OPT SW 35 TRK/SS3 C19 R61 ILIM3 IAVG3 C20 R35 0 mOhm 2010 0 6 36 VINVIN- 30 SW R59 R60 VIN+ 7V - 14V VOS1+ J4 R58 OPT PHASE 37 PGND J1 CIN2 180uF 16V COUT3-5,8-10,13-15,18-20: Panaasonic EEFSX0E331ER (330uF, 2.5V, 9mOhms) 31 SW OPT OPT OPT OPT R1-4 OPT VSNSOUT4 7 8 IAVG4 38 PHASE VIN ISNS4P 39 PGND 15 C14 0.22uF C15 IAVG2 R57 ILIM2 C16 TRK/SS2 C17 U3 FDMF5820DC PGND 14 7 VSNSN4 40 13 R48 OPT GL 19 RB-4 VOS4OPT R31 0 mOhm 2010 R45 10K PGND 8 50 49 PWM2 PGOOD1 52 51 ISNS4N VSNSP4 C7 2.2uF 16V GL 8 JP4 RUN2 ISNS3N VSNSOUT4 41 12 + Sanyo 16SVP180MX (180uF, 30mOhms, 3.02A, 16V) C5 10uF 0805 E8 PGND SW C32 OPT 53 ISNS3P VSNSOUT3 42 C13 0.22uF COMP4 2 3 RUN1 VSNSN3 OPT R78 OPT 1 PWM1 IAVG3 VIN RUN4 OPT CLKOUT VSNSP3 44 43 43.2K 100pF CIN1 180uF 16V VIN+ VOS1- PVCC SW RT-4 OPT 56 ILIM3 RB-3 VOS3OPT TRK/SS4 E17 COUT3 COUT4 COUT5 330uF 2.5V 1 PGND 18 VOS4+ RT-3 OPT 55 TRACK/SS3 COMP3 SGND VOS3+ E14 54 FB3 59 R68 100K PGOOD4 24 E6 R29 10 VOUT1 0.25uH 744301025 25 SW VIN VIN 19 PGOOD2 45 R51 C11 DATE 10-21-15 VOS1+ C40 OPT L1 26 SW TMON SW 18 5VBIAS TRACK/SS4 27 EN/FAULT# 17 17 VCC 2 PGOOD3 35 SW VIN 16 R2-3 OPT 16 C2-3 OPT VINSNS 47 46 ILIM1 IAVG1 34 CIN5 CIN6 22uF 25V 1210 ILIM4 VSNSOUT3 C3-3 OPT C1-3 OPT R1-3 OPT TRACK/SS2 FB2 PGOOD3 R3-3 OPT R65 OPT 1% 15 COMP2 48 29 RUN3 ILIM2 28 13 IAVG2 VSNSP2 RUN3 12 VSNSN2 27 11 FB3 COMP3 C1-2 OPT 9 10 ISNS2P PWM3 COMP2 FB2 ISNS1N VSNSOUT2 PGOOD4 JP3 C18 1uF 8 14 2 C25 OPT C2-2 OPT 7 PWM4 3 VOS2- IAVG1 ISNS1P ISNS2N RUN4 OFF RB-2 OPT ILIM1 SGND TRACK/SS4 ON 1 R3-2 OPT R63 OPT RUN3 OPT R2-2 OPT R1-2 OPT 6 24 VIN RT-2 OPT VSNSOUT1 5 20 E13 C3-2 OPT 4 33 Mike S. CIN3-10: Murata GRM32ER71E226K (22uF, 16V, X5R, 1210) R28 24.9K C4 2.2uF 16V 28 GL VIN 11 U1 LTC7851EUHH VSNSN1 23 TRK/SS3 VOS2+ VSNSP1 3 VCC 1 VSNSOUT2 2 RB-1 VOS110.0K 22 R54 RT-1 10.0K COMP1 FREQ FB1 VOS1+ 5VBIAS 1 COMP4 COMP1 VIN 10 RUN1 RUN2 CLKIN 220pF E10 TRACK/SS3 30 R47 0 9 58 PGOOD2 TRK/SS1 2.2nF C2-1 R50 100K 0 C8 0.22uF C1-1 R2-1 4.12K 5VBIAS 3 R44 30.9K 26 R46 OPT 1% 57 C9 OPT TRACK/SS1 3 2 C6 OPT FB4 OFF CIN1,2: 0 R42 R3-1 332 3.3nF R1-1 10.0K RUN2 25 R43 OPT R41 Fsw = 400kHz FB1 C3-1 21 1 VSNSOUT1 APPROVED 4 TP1 29 GL U2 FDMF5820DC E3 E5 R39 10 VIN JP2 1 6 VIN PGND 15 RUN2 OPT OFF 5 PVCC R40 ON ON NC TMON VIN PGND 12 DESCRIPTION PRODUCTION J2 TRK/SS2 E9 2 R11 10K 31 EN/FAULT# VIN E7 TRACK/SS2 7 VIN BOOT 9 R9 OPT 1 PGOOD1 TP5 TRK/SS4 R27 IAVG4 5VBIAS R30 100K TRK/SS3 R26 SW 0 IAVG1 TRK/SS2 R25 + 23 FB4 ILIM4 R24 R7 10K SW 0 0 0 ILIM3 R23 22 JP1 R21 ILIM2 R22 TRK/SS1 SW C3 OPT 0 21 R19 R20 10k 1% R18 0 20 OFF 3 2 R17 0 ILIM1 FB3 RUN1 R16 0 SW R15 18.2K R6 0 19 ON 1 R5 0 FB2 4 RUN1 R4 C1 2.2uF 16V C2 0.22uF SW R10 0 RUN4 18 VIN FB1 RUN3 8 E4 OPT RUN2 VIN R8 RUN1 COMP4 PHASE VCC TRK/SS1 COMP3 0 SW TRACK/SS1 COMP2 R3 SW COMP1 REV __ VIN Components to parallel two or more phases 17 Place these components on edge of board ECO 1 0 AGND R2 SW CLKIN E1 DATE: Tuesday, February 09, 2016 E SHEET 1 REV. 2 OF 2