A B C D E REVISION HISTORY ECO REV DESCRIPTION APPROVED DATE 2 PRODUCTION TOM G. 06-03-10 __ RTR1 CSS1 VIN SVIN RSS1 1 2 TRACK 3 4 EXT SS 5 6 INT SS ICMP RUN1 J1 4.7M 0.01uF SVIN COMP1 JITH1 ECMP 2 3 4 CFFW1 VIN 1 RPG1 100k TP3 20 SW1 19 Ith1 CIN1 22uF 6.3V 1206 RITH1 43.2k 1% C1 10pF CFILT 1uF RFILT 24 3 ON 2 SVin 9 PGOOD2 TP10 PVin1 23 SW2 16 PGood2 13 100k 7 15 1 4.7M Track/SS2 INT SS 1 4 RTR2 TRACK 5 6 100k TRACK1 7 8 TRACK2 TP9 RM4 100k 1% ECBM JP4 USER SELECT Rt/Sync VOUT2 VOUT2 3A 11 SW2 12 Ith2 6 0.47uH VISHAY IHLP2020BZERR47M11 COUT2 47uF 6.3V 1210 COUT4 10uF 6.3V 0805 COUT8 100uF 6.3V OPT 3 TP6 + COUT6 100uF OPT GND FB2 5 25 8 17 3 10pF CFFW2 ECMP 3 4 ICMP 1 2 TP7 R2 COMP2 C2 2 EXT SS 3 3 3.3V JITH2 4 1 0.01uF EBMCV J9 1 JP3 R9 Run2 J4 TRACK / SS2 RSS2 RM3 301k 1% 2.5V R7 2 GND TP15 JP2 267k 1% CITH1 220pF VIN CSS2 R1 845k 1% L2 PVin2 PVin2 4 TP5 OPT 10 RPG2 FB1 COUT5 100uF OPT 1.8V R5 PVin1 22 PGND CIN2 22uF 6.3V 1206 SGND CIN3 22uF 6.3V 1206 SRLim CIN4 22uF 6.3V 1206 Mode CIN5 100uF + OPT + 10pF 187k 1% Phase + TP2 OFF PGood1 SW1 VIN GND RUN2 J2 Run1 21 TP1 CIN6 100uF 3 Track/SS1 14 18 PGOOD1 VIN 2.25V - 5.5V 24 JP1 R3 422k 1% LTC3615EUF 2 ON COUT7 100uF 6.3V OPT GND 1 3 U1 OFF COUT3 10uF 6.3V 0805 COUT1 47uF 6.3V 1210 TP4 2 RTR3 OPT 4 VOUT1 3A 0.47uH VISHAY IHLP2020BZERR47M11 J3 TRACK / SS1 SET 100k EXT TP11 VOUT1 L1 TRACK1 RT 200k 1% SVIN 10pF RITH2 43.2k 1% 348k 1% GND TP14 CITH2 220pF RTR4 OPT J6 RT / SYNC INT SYNC RT2 OPT 2 1 2 RT 3 4 EXT SYNC 5 TRACKING 6 J5 PHASE RTR5 VOUT1 316k 1% RTR6 105k 1% 180 deg OUT PH (OUT-OF-PHASE) 90 deg OUT PH (OUT-OF-PHASE) IN PHASE RM1 866k 1% 1 2 3 4 5 6 RM2 1.13M 1% 1 TP13 (BURST MODE EXTERNAL CLAMP VOLTAGE) 2 3 4 ADJ 5 6 MAX 7 8 2 JP6 R6 1.5V 232k 1% RSRLIM 100k 1% JP7 R8 1.8V 174k 1% JP8 R10 OPT 1 2 PSM 3 4 FCM 5 6 ECBM 7 8 ICBM ECBM NOTE: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE IN OHMS, 0603. ALL CAPACITORS ARE IN MICROFARADS, 0603. (PULSE-SKIP MODE) (FORCED CONTINUOUS MODE) (EXTERNAL CLAMP BURST MODE) (INTERNAL CLAMP BURST MODE) 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. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. A 1.2V 348k 1% USER SELECT J7 MODE ECBM BMECV SVIN MIN SYNC TP8 1 JP5 R4 J8 SRLIM B C APPROVALS PCB DES. A.K. APP ENG. TOM G. TECHNOLOGY 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only TITLE: SCHEMATIC DUAL 3A MONOLITHIC SYNCHRONOUS STEP-DOWN REGULATOR SIZE N/A SCALE = NONE D DATE: IC NO. REV. LTC3615EUF 2 DEMO CIRCUIT 1435A Thursday, June 03, 2010 SHEET 1 E OF 1 1