A B C D E REVISION HISTORY VIN ECO __ SNS1+ 25 C7 SNS1- R21 0.22uF SNS2R22 C8 SNS2+ 0.22uF 24 23 22 21 2 VDRV 1 3 SMOD# 41 4 GND BOOT 6 5 GH CGND 8 7 PHASE 9 42 NC 35 34 33 COUT4 COUT5 100uF 6.3V 1210 32 R20 2.87K 1% 31 VSWH + E13 VOUT1+ 1.5V / 25A VOUT1- U2 J4 R18 10 R26 1 VOS13 SMOD# VCIN VDRV BOOT GL PGND VSWH PGND VSWH U3 FDMF6820A PGND VSWH VSWH VSWH 40 R38 2.87K 1% 39 38 37 L2 0.47uH SW2 36 VOS2+ R39 10 VOUT2 35 34 COUT9 COUT10 100uF 6.3V 1210 WURTH EL. 744355147 33 32 31 VSWH PGND PGND R31 OPT 1 2 3 41 GND CGND 4 6 5 GH VSWH PGND R30 10K + 2 E8 COUT6 J5 COUT7 COUT8 330uF 2.5V J6 R43 10 30 20 CGND VSWH R41 VIN 29 19 THWN VSWH 17 DISB# VIN PGND 16 VIN 43 15 CIN6 22uF 16V 1210 PWM 28 CIN5 22uF 16V 1210 C35 16V DISBL#2 THDN2 VIN PGND 13 2.2uF R29 10K E12 VOS2+ VOUT2+ 1.2V / 25A VOUT2VOS2- VOS2- R45 18.2K 1% 2 RUN2 1 JP2 J3 VIN 1 3 COUT1 COUT2 COUT3 330uF 2.5V 2.2 PGND 12 OPT R42 OPT RUN2 OFF VOS1+ E4 R11 10 VOUT1 30 VSWH 29 VSWH PGND 43 PGND PGND 28 27 PGND PGND 26 25 PGND 24 PGND SW1 R44 100K PGOOD2 ON R25 27 11 SW2 18 VCC VOS1+ L1 0.47uH 744355147 WURTH EL. 36 VSWH 0.22uF C11 2.2uF 16V R28 OPT R37 34.0K 1% VCC VIN C9 21 E11 CLKOUT VIN- E2 5VBIAS R24 53.6k 1% VCC R40 OPT E10 CLKOUT J2 19 FSWITCH = 500kHz TYPICAL GND 4 VIN- E6 14 E9 7V - 14V VOS1- CLKIN CLKIN VIN+ J1 CIN2 180uF 16V 38 VSWH 26 2 + 0 0 R35 OPT C12 OPT CIN1 OPT SVP F8 ILIM2 20 R34 OPT + 37 VSWH PGND PHASE VCC PGND R7 OPT 39 VSWH U2 FDMF6820A PGND R6 10K 27 PWM2 C10 OPT PGND PGND 29 30 PWMEN1 32 33 31 PGOOD1 IAVG 34 VINSNS CONFIG PWM1 RUN2 VSWH PGND FB2 PGND 24 FB2 TRK/SS2 0 R33 OPT ILIM2 GL 7 R32 SGND COMP2 VSWH NC E7 R27 OPT VSNSP2 CGND 10 TRACK/SS2 9.31k C1-2 1.5nF ISNS2P GND R2-2 280 VOUT1 10 ISNS2N VSNSN2 37 R3-2 COMP2 ISNS1N VSNSOUT2 THWN PGND C2-2 100pF 20 DATE 12-14-11 VIN+ E1 DISBL#1 THDN1 VIN 23 9 C3-2 3.3nF 17 18 26 PWM2 8 VSNSOUT1 ISNS1P PWMEN2 10.0K 0 R1-2 10.0K 16 MIKE S. 40 PWM VIN 28 18 7 VSNSN1 17 6 U1 LTC3861EUHE PGOOD2 RT-2 R23 VOS2- ILIM1 SGND 16 RB-2 10k RUN1 VSNSP1 PHSMD 4 5 VOS2+ 15 CIN4 22uF 16V 1210 R17 53.6k 1% COMP1 15 3 CLKOUT 2 10.0K CLKIN VOS1- RB-1 FB1 14 1 VOS1+ RT-1 15.0K 35 36 C1-1 COMP1 1.5nF VCC C2-1 100pF ILIM1 CIN3 22uF 16V 1210 FB1 13 R19 0 3 10.0K R1-1 9.76k R15 OPT 19 TRACK/SS1 3.3nF R2-1 280 R13 0 C5 OPT FREQ R3-1 C4 OPT 14 8 C6 1uF 1 C3-1 VCC R16 TRACK/SS2 R14 OPT 13 VIN 5VBIAS 12 0 11 E5 R10 OPT PWM1 R9 0 C34 2.2uF 16V DISB# PGND TRK/SS1 R12 APPROVED VIN R5 10K VIN 23 12 IAVG TRACK/SS1 R3 1 VIN 22 VIN 11 SW1 42 E3 VCC 21 PGOOD1 VIN R8 100K VIN 4 10 R73 0 VIN OPT VCC DESCRIPTION PRODUCTION R2 2.2 0.22uF C3 2.2uF 16V R72 22 VCC 9 R4 10k 1% C2 OPT JP1 VIN 3 OFF REV 2 5VBIAS C1 VCIN RUN1 2 PGND 1 ON 25 R1 18.2K RUN1 C13 OPT R46 10k 1% VOUT1 VOUT1 A CUSTOMER NOTICE OPTIONAL COMPONENTS FOR SINGLE OUTPUT DUAL PHASE APPLICATIONS R47 OPT VOUT2 R36 OPT 2010 VOUT2 2010 TRK/SS1 TRK/SS2 VCC COMP1 COMP2 RUN1 RUN2 R48 R53 R54 OPT OPT OPT B FB1 R49 OPT FB2 R51 OPT VCC R50 R52 ILIM1 OPT ILIM2 OPT C IAVG C14 OPT 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 SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. D APPROVALS PCB DES. APP ENG. A.K. MIKE S. TECHNOLOGY TITLE: SCHEMATIC HIGH CURRENT DUAL OUTPUT SYNCHRONOUS BUCK CONVERTER SIZE LTC3861EUHE DEMO CIRCUIT 1822A N/A SCALE = NONE 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only DATE: IC NO. Monday, May 14, 2012 REV. 2 SHEET 1 E OF 3 1 A B C D HEADER/SOCKET TO PARALLEL DC1822A TO ANOTHER DC1822A OPTIONAL POWER BLOCK TEMP2+ NOTE: ALL PARTS WITHIN THIS ARE OPTIONAL 7VBIAS TEMP2- E14 R55 R74 R75 0 0 RUN1 15 SNS2+ TRACK/SS1 14 SGND +CSA PWM2 SGND 1 -CSA CLKIN 12 PWMA 11 10 PWMB 9 VINB 2 3 3 4 4 5 5 6 6 TRK/SS1 RUN1 COMP1 7 8 COMP2 IAVG MILL MAXX 802-40-008-20-001000 COUT13 COUT22 COUT23 100uF + 330uF + 330uF 6.3V 2.5V 2.5V 1210 COUT14 100uF 6.3V 1210 + COUT24 330uF 2.5V DYNAMIC LOAD CIRCUIT FOR VOUT1 Q1 SUD50N03-12P C22 C28 10uF 0805 1uF GND 2 OFF 3 1 2 6 BOOST SHDN NC FB R59 33uH C19 0 22uF 1206 C18 1uF 16V 1210 5 E22 E25 INT BIAS 5V / 200mA CLKOUT MILL MAXX 803-43-008-20-001000 8 R61 604K VOUT2 VOUT2 Q2 SUD50N03-12P J7 C29 10uF 0805 PULSE GEN2 E20 GND R58 10k 1% E23 J10 3 ISTEP2+ R60 E21 LOAD STEP 0.010 10mV / Amp 1% 2010 ISTEP2E24 UVLO CIRCUIT RUN1 RUN2 GND 7 C21 22pF R63 2 D1 BAV170 SOT23 5VBIAS R66 OPT 200k 4 JP3 BIAS L3 0.22uF 16V SW SGND NOTE: ALL PARTS WITHIN THIS ARE OPTIONAL 5VBIAS 3 1 ON VIN GND 3 C26 1uF E18 TEMP1- BIAS SUPPLY FOR LTC3861 AND DRMOS INT BIAS SGND 1 TEMP1+ 2 SGND DYNAMIC LOAD CIRCUIT FOR VOUT2 ISTEP1+ R57 E17 LOAD STEP 0.010 10mV / Amp 1% 2010 ISTEP1E19 R56 10k 1% E27 E26 C17 4 RUN2 VOUT1 PULSE GEN1 R62 U4 LT3470ETS8 VIN TRACK/SS2 VOUT1 7 -CSB OPT COMP2 VOUT1 16 7VBIAS 8 CLKOUT CLKIN E16 0 7 RUN2 TRK/SS2 IAVG C16 6 GND +CSB 1 5 VOUTB 0 R77 COUT17 330uF VOUT2 2.5V 1 2 7VBIAS 4 +7V SNS1R76 COUT16 330uF 2.5V 4.7uF 0805 8 SNS1+ COUT15 330uF 2.5V 2 PWM1 CIN10 22uF 16V 1210 GND TEMPB CIN9 22uF 16V 1210 3 VOUTA + VIN CIN8 22uF 16V 1210 2 GND COUT11 100uF 6.3V 1210 + CIN7 22uF 16V 1210 VINA COUT12 100uF 6.3V 1210 + 13 3 SGND TEMPA SNS2- IAVG COMP1 1uF PB1 D12S1R845A DC/DC Converters J9 RIGHT ANGLE SOCKET J8 RIGHT ANGLE HEADER E15 C15 OPT 4 E VOUT1 R65 THDN1 OPT R67 THDN2 OPT VOUT2 R82 OPT R83 OPT OPTIONAL BIAS SUPPLY FOR POWER BLOCK VIN 3 PWR BLK BIAS C20 1 1uF ON 2 3 OFF JP4 1 2 VIN 6 SHDN NC SW BIAS FB 7VBIAS 0.22uF L4 R64 16V 33uH C25 0 22uF 1206 C24 1uF 16V 1210 5 E28 PWR BLK BIAS 7V / 200mA CUSTOMER NOTICE 7 8 R69 953K C27 22pF APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. R71 200k 4 1 C23 BOOST U5 LT3470ETS8 GND NOTE: ALL PARTS WITHIN THIS ARE OPTIONAL THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. A B C D A.K. MIKE S. TECHNOLOGY TITLE: SCHEMATIC HIGH CURRENT DUAL OUTPUT SYNCHRONOUS BUCK CONVERTER SIZE LTC3861EUHE DEMO CIRCUIT 1822A N/A SCALE = NONE 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only DATE: IC NO. Wednesday, March 28, 2012 REV. 2 SHEET 2 E OF 3 1 A B C D E OPTIONAL DISCRETE GATE DRIVER AND MOSFETS FOR PHASE 1 NOTE: ALL PARTS WITHIN THIS ARE OPTIONAL VIN D2 4 R79 8 6 5 PWM1 C30 0.22uF BOOST 7 TS VLOGIC BG IN Q4 BSC050NE2LS 5 4 CIN11 22uF 16V 1210 5 CIN12 22uF 16V 1210 4 4 1 2 3 1 2 3 SW1 1 TG VCC 2 Q5 BSC010NE2LS 3 4 GND C31 2.2uF 16V Q3 BSC050NE2LS CMDSH-3 U8 LTC4449EDCB 5VBIAS R78 2.2 0 Q6 BSC010NE2LS 5 4 5 4 GND 1 2 3 1 2 3 9 3 3 OPTIONAL DISCRETE GATE DRIVER AND MOSFETS FOR PHASE 2 NOTE: ALL PARTS WITHIN THIS ARE OPTIONAL VIN D3 R80 8 7 2 6 5 PWM2 BOOST C32 0.22uF TG VCC TS VLOGIC BG IN C33 2.2uF 16V GND GND Q7 BSC050NE2LS CMDSH-3 U9 LTC4449EDCB 5VBIAS R81 2.2 0 5 Q8 BSC050NE2LS 4 5 CIN13 22uF 16V 1210 CIN14 22uF 16V 1210 4 1 2 3 1 2 3 1 SW2 2 3 4 Q9 BSC010NE2LS 5 Q10 BSC010NE2LS 4 5 2 4 1 2 3 1 2 3 9 1 CUSTOMER NOTICE APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. 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 SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. A B C D A.K. MIKE S. TECHNOLOGY TITLE: SCHEMATIC HIGH CURRENT DUAL OUTPUT SYNCHRONOUS BUCK CONVERTER SIZE LTC3861EUHE DEMO CIRCUIT 1822A N/A SCALE = NONE 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only DATE: IC NO. Wednesday, December 14, 2011 E REV. 2 SHEET 3 OF 3 1