A B C D E REVISION HISTORY INTVCC R73 100K 15 13 3 OFF 1 SMOD# VCIN VDRV 2 3 4 41 GND BOOT 5 6 GH CGND 7 8 SW1 34 COUT4 COUT5 100uF 6.3V 1206 32 VSWH 31 R20 4.64K 1% R51 931 1% + COUT2 COUT1 COUT3 330uF 2.5V VOUT1+ 1.5V / 30A VOUT1- R21 0 J4 R18 3 E6 VOS1- VOS1- SNS2- SMOD# VCIN 1 2 3 VDRV GND BOOT 4 41 5 6 GH VIN CGND VSWH GL PGND VSWH PGND VSWH U3 FDMF6820A PGND PGND VSWH VSWH THDN2 40 39 R42 4.64K 1% TP6 38 R38 931 1% SW2 36 35 34 33 L2 0.33uH VOUT2 WURTH EL. 744301033 COUT10 COUT9 100uF 6.3V 1206 32 31 VOS2+ R39 R22 0 37 E8 10 + COUT8 J5 COUT7 COUT6 330uF 2.5V VSWH J6 VOS2+ VOUT2+ 1.2V / 30A VOUT2- R43 30 VSWH R45 40.2K VSWH VSWH PGND PGND 29 17 THWN PGND 16 DISB# 43 CIN6 22uF 16V 1210 15 R31 OPT R30 10K 2 VIN PGND CIN5 22uF 16V 1210 SW2 C35 2.2uF 16V PWM2 PWM VIN 28 13 VIN PGND 12 R46 10K E12 VOS2- VOS2- R88 100K OPTIONAL COMPONENTS FOR DUAL PHASE CONVERTER VOSNS1 E13 VOSNS2 R53 NOTE: UNLESS OTHERWISE SPECIFIED A J3 R26 1 R29 10K TP4 CGND 11 7 R44 OPT PHASE VIN2 R41 10K 5VBIAS R25 2.2 0.22uF C11 2.2uF 16V PWM2 20 1. ALL RESISTORS ARE IN OHMS, 0603. ALL CAPACITORS ARE 0603. VIN- VOS1+ E4 10 VOUT1 33 30 VSWH VSWH 29 PGND 43 PGND 28 PGND 27 PGND 26 PGND 25 PGND 35 10 INTVCC 7V - 14V VOS1+ R11 L1 0.33uH 744301033 WURTH EL. SNSDC2+ C9 R87 OPT C10 0.01uF C13 0.1uF JP2 PGOOD2 CIN1 180uF 16V TP5 36 C38 0.22uF 37 27 2 + 37 11 21 ON CIN2 180uF 16V SNSAC2+ 19 RUN2 1 + J1 38 C37 0.22uF 12 VIN RUN2 VIN- SNS1SNSAC1+ 18 E10 4 VIN+ 1m Ohm 2512 14 R85 10K HIZB2 VIN R50 C36 0.22uF 16 PGND VIN2 VIN2 J2 39 DATE 7-17-13 1m Ohm 2512 E2 THDN1 MIKE S. 10 14 R33 OPT R52 OPT APPROVED VIN1 SNSDC1+ 26 E7 C47 22pF VSWH VSWH PGND 17 VOS2+ R40 10K VSWH PGND PGND R27 OPT TK/SS2 TRACK/SS2 C48 OPT VOSNS2 PHASE PGND VIN VOUT1 VSWH U2 FDMF6820A PGND 25 GND NC 9 PGND E30 R6 10K DESCRIPTION PRODUCTION 40 C40 0.22uF 18 2 1 VSWH 5VBIAS TP3 C41 330pF VOS2- PGND 10 9 RUN2 PWM2 8 GND SNSDC2+ PWMEN2 7 HIZB2 6 TK/SS2 SNS2- ITEMP2 ITH2 GL 21 20 21 22 23 24 25 26 VIN C12 1uF CGND VSWH 19 GND RUN1 PWM1 PWMEN1 HIZB1 TK/SS1 VOSNS1+ SNSAC2+ R35 2.2 27 PGOOD2 INTVCC ILIM2 VIN 10 R37 8.06K CLKOUT 5 R34 OPT VIN PGOOD1 VOSNS2+ R28 OPT 36 SNS1- MODE/PLLIN ITEMP2 R32 OPT 35 SNSDC1+ SNSAC1+ 1 R24 OPT C8 4.7uF 10V 0805 THWN U1 LTC3774EUHE FREQ 4 34 INTVCC 20 PHMODE VOSNS2- 33 ILIM1 3 32 VOSNS1- 28 31 37.4K ITH1 ITEMP1 R17 OPT 30 ITH2 FSW = 400kHz R23 TP2 2 29 C14 2.2nF 17 18 ITEMP1 C7 330pF C6 2.2nF C5 0.01uF CLKOUT E11 16 19 CLKIN E29 CLKOUT 15 SW1 DISB# 24 R19 8.06K ITH1 3 PLLIN R15 OPT CIN4 22uF 16V 1210 PWM VIN PGND VOS1- 14 CIN3 22uF 16V 1210 C34 2.2uF 16V PWM1 VIN 24 NOTE: REMOVE JUMPER AT JP5 FOR BURST MODE. R89 INTVCC MODE 10K 1 PS 2 BM 3 CCM R16 OPT JP5 R10 OPT R9 10K C45 OPT 12 13 PWM1 PGND VOSNS1 5VBIAS 15.0K 8 C46 22pF NC R14 OPT PGND VOS1+ 0 2 R49 VIN2+ R5 10K TP1 VIN 9 R12 E5 R8 23 11 TK/SS1 VIN 10 VIN E9 TRACK/SS1 42 VIN1 R7 10K HIZB1 REV __ R3 C3 2.2uF 16V 22 JP1 E1 ECO 1 R4 10K VIN 4 C2 0.1uF VIN1 42 3 VIN 2 OFF RUN1 R1 40.2K 1 VIN1+ 5VBIAS C1 R2 0.22uF 2.2 22 ON VIN VIN E3 RUN1 23 PGOOD1 B VOS2- RUN1 VOUT1 ITH2 R47 OPT R68 OPT VOS1- ITH1 RUN2 OPT TK/SS1 TK/SS2 R92 R54 R48 OPT OPT OPT 2512 R36 OPT 2512 C VOUT2 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. APPROVALS PCB DES. APP ENG. TECHNOLOGY LT MIKE S. TITLE: SCHEMATIC HIGH EFFICIENCY DUAL OUTPUT STEP-DOWN CONVERTER WITH VERY LOW DCR INDUCTOR SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. D 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. REV. LTC3774EUHE DEMO CIRCUIT 2002A Wednesday, July 17, 2013 2 SHEET 1 E OF 3 1 A B C R55 R74 0 14 TRACK/SS1 15 VOS1- SGND +CSA -CSA SGND 1 CLKIN CIN8 22uF 16V 1210 12 CIN9 22uF 16V 1210 PWMA VOUTA GND +7V PWMB 9 8 VOUTB VINB GND +CSB -CSB COUT16 330uF 2.5V COUT17 330uF VOUT2 2.5V COUT14 100uF 6.3V 1206 6 5 6 4 VOS2- 5 RUN2 RUN2 6 7 7 8 8 CLKIN TRACK/SS2 4 VOS2- CLKOUT SGND SGND CLKOUT MILL MAXX 803-43-008-20-001000 MILL MAXX 802-40-008-20-001000 VOUT1 COUT13 COUT18 COUT19 100uF + 330uF + 330uF 6.3V 2.5V 2.5V 1206 + COUT20 330uF 2.5V OPTIONAL NTC COMPENSATION NETWORK FOR DCR SENSING ITEMP1 OPTIONAL UVLO CIRCUIT ITEMP2 NOTE: ALL PARTS WITHIN THIS BLOCK ARE OPTIONAL U8 0 LTC4449EDCB 16V 8 R90 2.2 7 6 5 C30 0.22uF BOOST TG VCC TS VLOGIC BG IN GND GND 1 2 NOTE: ALL PARTS WITHIN THIS BLOCK ARE OPTIONAL Q4 BSC050NE2LS 5 4 5 CIN11 22uF 16V 1210 CIN12 22uF 16V 1210 5VBIAS 4 R66 OPT R65 OPT R67 OPT VOUT2 R83 OPT R82 OPT 1 2 3 1 2 3 Q6 BSC010NE2LS 5 4 5 5VBIAS R91 2.2 C44 2.2uF 7 6 5 TG VCC TS VLOGIC BG GND 1 C32 0.22uF 16V 9 PWM1 Q8 BSC050NE2LS 5 CIN13 22uF 16V 1210 CIN14 22uF 16V 1210 2 4 1 2 3 1 2 3 SW2 2 Q9 BSC010NE2LS 3 4 5 Q10 BSC010NE2LS 4 GND 1 2 3 5 4 BOOST IN Q7 BSC050NE2LS CMDSH-3 0 U9 LTC4449EDCB 16V 4 1 2 3 R80 8 SW1 Q5 BSC010NE2LS VIN2 D3 R81 2.2 C33 2.2uF 2 4 R84 OPT VOUT1 OPTIONAL DISCRETE GATE DRIVER AND MOSFETS FOR PHASE 2 1 3 R70 RN2 OPT OPT THDN2 TEMP1- Q3 BSC050NE2LS CMDSH-3 5VBIAS THDN1 D1 OPT BAV170 SOT23 3 RN1 OPT TP10 D2 R79 RUN1 RUN2 1 TP9 VIN1 R78 2.2 R86 OPT 2 16 C22 1uF OPTIONAL DISCRETE GATE DRIVER AND MOSFETS FOR PHASE 1 16V 4 VOSNS2 3 TK/SS2 7 TEMP1+ C43 2.2uF TK/SS1 VOS1RUN1 R72 OPT OPT 5VBIAS 3 ITH2 2 VOSNS2 5 7VBIAS C31 2.2uF 1 ITH2 VOSNS1 7VBIAS C16 4 R62 5VBIAS ITH1 2 2 0 2 1 3 C42 0.047uF R77 SNS1- 3 COUT15 330uF 2.5V 4.7uF 0805 10 R76 3.32k SNSDC1+ 2 COUT12 100uF 6.3V 1206 1 VIN1 PWM1 SNSAC1+ CIN10 22uF 16V 1210 GND TEMPB CIN7 22uF 16V 1210 VINA COUT11 100uF 6.3V 1206 + 13 11 3 VOSNS1 RUN1 TEMPA R75 COUT15-20: Sanyo 2R5TPE330M9 COUT11-14: Murata GRM31CR60J107ME39L CIN7-10: MURATA GRM32ER61C226KE20L 1uF PB1 D12S1R845A DC/DC Converters C39 0.047uF 3.32k SNSAC2+ PWM2 VIN2 ITH1 OPT + SNSDC2+ TEMP2+ TEMP2C15 TP7 TP8 7VBIAS J9 RIGHT ANGLE SOCKET J8 RIGHT ANGLE HEADER + SNS24 E HEADER/SOCKET TO PARALLEL DC2002A TO ANOTHER DC2002A OPTIONAL POWER BLOCK NOTE: ALL PARTS WITHIN THIS BLOCK ARE OPTIONAL D 5 4 1 2 3 1 2 3 9 PWM2 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. TECHNOLOGY LT MIKE S. TITLE: SCHEMATIC HIGH EFFICIENCY DUAL OUTPUT STEP-DOWN CONVERTER WITH VERY LOW DCR INDUCTOR SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. A B C D 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. LTC3774EUHE DEMO CIRCUIT 2002A Wednesday, July 17, 2013 REV. 2 SHEET 2 E OF 3 1 A B 3 INT BIAS 4 C26 1uF 1 ON 2 OFF 3 1 2 VIN SHDN NC R59 0 16V 33uH 1206 C19 22uF 16V 1210 SW FB 5 DYNAMIC LOAD CIRCUIT FOR VOUT1 5VBIAS E22 C18 1uF E25 D INT BIAS 5V / 200mA GND 8 R61 604K E DYNAMIC LOAD CIRCUIT FOR VOUT2 VOUT1 Q1 SUD50N03-12P PULSE GEN1 E16 R56 10k 1% 7 C21 22pF R63 GND 200k 4 JP3 L3 BIAS GND VIN BOOST U4 LT3470ETS8 C17 0.22uF 6 BIAS SUPPLY FOR DRMOS C E18 VOUT2 VOUT2 Q2 SUD50N03-12P VOUT1 C28 J7 10uF 0805 C29 J10 10uF 0805 PULSE GEN2 E20 ISTEP1+ R57 E17 LOAD STEP 0.005 5mV / Amp 1% 2010 ISTEP1E19 GND 4 R58 10k 1% E23 ISTEP2+ R60 E21 LOAD STEP 0.005 5mV / Amp 1% 2010 ISTEP2E24 OPTIONAL BIAS SUPPLY FOR POWER BLOCK VIN 3 3 PWR BLK BIAS 1 ON 2 OFF 3 VIN L4 16V 33uH R64 0 C25 1206 22uF 16V 1210 6 C23 0.22uF SW 5 7VBIAS PWR BLK BIAS E28 C24 1uF 7V / 200mA 3 1 2 SHDN NC BIAS FB 7 8 R69 953K C27 22pF R71 200k 4 JP4 C20 1uF BOOST U5 LT3470ETS8 GND NOTE: ALL PARTS WITHIN THIS ARE OPTIONAL 2 2 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. TECHNOLOGY LT MIKE S. TITLE: SCHEMATIC HIGH EFFICIENCY DUAL OUTPUT STEP-DOWN CONVERTER WITH VERY LOW DCR INDUCTOR SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. A B C D 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. LTC3774EUHE DEMO CIRCUIT 2002A Wednesday, July 17, 2013 REV. 2 SHEET 3 E OF 3 1