5 4 3 2 1 REVISION HISTORY ECO REV DESCRIPTION DATE 3 PRODUCTION 05/14/10 D L1 10uH CDRH104RNP-100NC E8 25 EN/UVLO 1 SYNC 2 NO SYNC E5 R2 95.3k 1% 0402 3 34 E1 INTVCC INTVCC 28 SYNC FBX U1 INTVCC R4 41.2k 1% 300kHz 33 NC 0402 NC C7 22nF 0402 NOTES: UNLESS OTHERWISE SPECIFIED, 1. ALL CAPACITORS AND RESISTORS ARE 0402. 2. ALL CAPACITOR VALUES ARE IN MICROFARADS. 3. ALL RESISTOR VALUES ARE IN OHMS. CUSTOMER NOTICE 31 1 2 10 35 36 GND CONTRACT NO. LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A APPROVALS CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. MI VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL ENG. KEITH S. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. 4 C 12 GND 13 GND GND 14 15 GND GND 16 SGND SGND SGND 6 C11 OPT 0402 C8 0.33uF 0603 THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 VOUT C6 24V @ 600mA 4.7uF 50V 1210 E7 GND B 17 37 23 R3 6.8k 0402 NC SGND C12 OPT 0402 VC 4 30 B A RT 24 SGND NC SS E9 C5 4.7uF 50V 1210 R6 15.8k 1% 0402 NC 32 SGND R5 226k 1% 0402 C10 OPT 0402 LT3957EUHE C9 4.7uF 10V 0603 E2 C4 4.7uF 50V 1210 3 R7 0 0402 SENSE1 JP1 C3 4.7uF 50V 1210 8 SENSE2 C13 OPT 0402 SYNC E6 3 SW 9 20 21 38 EN/UVLO SW GND SW E10 C2 2.2uF 50V 1210 SW R1 200k 1% 0402 GND C1 2.2uF 50V 1210 27 E4 VIN VIN 4.5V - 20V KEITH S. D D1 PDS360 2 SW E3 C 1 APPROVED 3 TECHNOLOGY 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only TITLE: SCHEMATIC A BOOST, FLYBACK, SEPIC AND INVERTING CONVERTER WITH 5A, 40V SWITCH SIZE LT3957EUHE DEMO CIRCUIT 1544A IC NO. N/A DATE: Friday, May 14, 2010 2 SHEET 1 REV 3 1 OF 1