1 2 3 4 5 6 7 8 REVISION HISTORY ECO REV DESCRIPTION 2 DATE PROD 08/03/09 APPROVED CZ INTVCC MODE PS BM CCM R4 1 2 INTVCC 4 E5 JP3 10K VIN+ 3 E19 R1 A 0 CIN1 180uF 16V OPT VFB1 VFB1 + J2 0 2 R27 SHT 2 VIN 4.5V-14V VIN C1 1 SYNC A J1 E1 GND E6 R29 100 VIN- R30 100 Q1 RJK0305DPB VIN S1+ SHT 2 ITH1 RUN1 E9 TRK/SS1 R3 C41 0 R2 0.1uF R31 C42 15K 220pF C43 220pF C44 R34 1nF 0 12K C TRK/SS1 ITH1 3 ITH1 ITH2 6 TRK/SS2 7 RUN2 ITH2 TRK/SS2 11 RUN2 SENSE1+ 31 SW1 26 TG1 25 BOOST1 24 BG1 23 VIN 22 INTVCC 21 BG2 19 PGND 18 BOOST2 17 5 6 7 8 1 2 3 1nF VOUT1 S1+ C20 TG1 SHT 2 0.1uF D1 0 R18 2.2 13 ILIM TG2 16 20 EXTVCC SW2 15 SENSE2+ 10 0.1uF R25 GND VO1- BG1 SHT 2 C11 4.7uF BG2 SHT 2 Q3 RJK0305DPB 0 CMDSH-3 VIN TG2 SHT 2 RUN2 SENSE2- 0.1uF C15 SW2 SHT 2 VO2+ L2 RS2 J5 1nF VOUT2 S2S2+ SHT 2 S2- ILIM E3 R39 100 EXTVCC EXTVCC E13 VL2- 10uF 4 1 2 3 VID11 CIN3 C21 S2+ 9 0.47uH 0.002 COUT4 100uF 6.3V Q4 RJK0330DPB SHT 2 4 + COUT5 220uF 4V + COUT6 220uF 4V C36 4.7uF 6.3V R40 100 1uF GND VOUT2 1.2V / 15A J6 C GND E14 C50 E2 B J4 E12 5 6 7 8 PGOOD 4 vosense2 SHT 2 TRK/SS2 VOUT1 1.5V / 15A C32 4.7uF 6.3V + COUT3 220uF 4V D2 8 0.1uF SGND OPT 14 VID12 C47 5 R37 + COUT2 220uF 4V VIN INTVCC C17 COUT1 100uF 6.3V INTVCC CMDSH-3 VINF 0.002 Q2 RJK0330DPB 4 R9 0.47uH 5 6 7 8 32 J3 1 2 3 SHT 2 RUN1 SENSE1- 5 6 7 8 TRK/SS2 SHT 2 30 2 R35 OPT R36 FREQ RS1 ITH2 SHT 2 VOUT1 E10 29 TRK/SS1 1nF C2 OPT MODE/PLLIN VO1+ L1 1 2 3 SHT 2 B VID21 27 E11 VL1- 4 SW1 SHT 2 C14 vosense1 R7 162K 1% SHT 2 TRK/SS1 S1- 1 28 12 RUN1 33 SHT 2 CIN2 10uF LTC3865EUH VID22 SHT 2 VID21 SHT 2 S1- U1 SHT 2 VID22 VO2INTVCC R43 0 VFB2 R46 R33 100K E4 PGOOD OPT PGOOD SHT 2 VID11 SHT 2 VID12 SHT 2 VFB2 CUSTOMER NOTICE D LINEAR TECHNOLOGY HASMADE 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. COMPONENTSUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. NOTES: UNLESS OTHERWISE SPECIFIED, 1. DO NOT APPLY LOAD FROM THE VO1+ TO VO1- OR FROM THE VO2+ TO VO2- TURRETS. THESE ARE ONLY INTENDED TO KELVIN SENSE THE OUTPUT VOLTAGE ACROSS COUT1 AND COUT4. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USEWITH LINEAR TECHNOLOGY PARTS. 1 2 3 4 5 6 CONTRACT NO. APPROVALS PCB DES. ENG. TECHNOLOGY MI CZ 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only TITLE: SCHEMATIC DUAL 15A SYNCHRONOUS BUCK CONVERTER WITH VIDS SIZE IC NO. LTC3865EUH DEMO CIRCUIT 1479A Thursday, December 03, 2009 DATE: 7 REV 2 SHEET 8 1 OF 2 D 5 6 7 8 VIN SHT 1 SW1 VIN OPT Q6 OPT R26 RUN1 4 BG1 1 2 3 SHT 1 4 1 2 3 TG1 5 6 7 8 SHT 1 CIN4 Q5 OPT VID11/VID21 VIN VID12/VID22 VOUT1/VOUT2 (V) ON 1 2 OFF 3 OPT RUN1 SHT 1 C38 5 6 7 8 JP1 SW2 SHT 1 BG2 1 2 3 SHT 1 4 Q8 OPT 5.0 (Vin > 5V) INTVCC FLOAT 3.3 R28 OPT OPT OPT VIN 5 6 7 8 TG2 INTVCC 2.5 GND INTVCC 4 R38 1 2 3 SHT 1 CIN5 Q7 OPT INTVCC INTVCC ON OFF 0.6 or external divider FLOAT FLOAT R64 OPT 1.8 INTVCC FLOAT RUN2 FLOAT GND 1.5 GND INTVCC 1.2 OPT 1 2 RUN2 SHT 1 3 JP2 C48 R41 OPT OPT E16 SHT 1 VID11 VID11 R66 OPT R42 INTVCC ILIM SHT 1 OPT GND FLOAT 1.0 GND GND 1.1 R44 OPT INTVCC R63 OPT E15 SHT 1 R45 SW1 VID21 VID21 S1+ SHT 1 OPT OPTIONAL DCR SENSING R65 10K R47 R49 ITH1 OPT S1- SHT 1 S1- VL1- R68 OPT SW2 S2+ SHT 1 SHT 1 OPT R55 RUN1 S2- SHT 1 S2- TRK/SS2 SHT 1 R53 R62 VID12 OPT R52 TRK/SS1 OPT OPT E18 VID12 SHT 1 VFB2 SHT 1 R51 NOTE: WHEN DCR SENSING IS IMPLEMENTED, SHORT RSENSE1 AND RSENSE2. DO NOT STUFF R29,R30,R39 AND R40 OPT R50 VFB1 OPT INTVCC ITH2 SHT 1 R61 SHT 1 OPTIONAL JUMPERS FOR SINGLE OUTPUT/DUAL PHASE OPERATION SHT 1 RUN2 OPT OPT VL2- R70 10K INTVCC R67 10K E17 SHT 1 1 X1 1 X2 1 X3 VID22 VID22 R69 OPT Represents Tooling Holes on PCB CUSTOMER NOTICE CONTRACT NO. 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 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. PCB DES. ENG. TECHNOLOGY MI CZ 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only TITLE: SCHEMATIC DUAL 15A SYNCHRONOUS BUCK CONVERTER WITH VIDS SIZE B DATE: IC NO. LTC3865EUH REV DEMO CIRCUIT 1479A Thursday, December 03, 2009 SHEET 1 2 OF 2