5 4 3 2 1 REVISION HISTORY ECO REV _ 2 DESCRIPTION PRODUCTION APPROVED DATE MOLLY Z. 05-22-12 D D L1 3.3uH + C4 100uF 50V C3 10uF 50V 1210 GND E4 SUNCON 50CE100BS NC C6 10nF 5 SW 6 SW 7 SW 4 BOOST 3 OUT 1 FB 16 SYNC 14 RT 9 8 D1 PDS360 VOUT R1 1.00M 1% C5 10pF C1 47uF 10V 1210 C7 1uF 16V 0603 R2 576k 1% R5 78.7k 1% (600kHz) C 17 C2 0.47uF 0603 IHLP2020CZER3R3M01 2 3 E3 NC 10 11 VIN 12 VIN VIN 15 PG 13 EN 2 SS VIN GND VIN 4.3V - 42V 1 U1 LT3975EMSE 3 2 1 E1 VOUT 3.3V / 2.5A E2 GND E7 SYNC C JP2 SYNC RT FREQ R6 200K PG E6 EN E5 JP1 ON B OFF 1 2 3 R7 OPT 0603 B R8 OPT 0603 CUSTOMER NOTICE NOTES: UNLESS OTHERWISE SPECIFIED A 1. ALL RESISTORS ARE 0402. ALL CAPACITORS ARE 0402. 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 JW MOLLY Z. TITLE: SCHEMATIC 5 4 3 IC NO. N/A SCALE = NONE A 42V, 2.5A, 2.7m A MICROPOWER BUCK REGULATOR SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only REV. LT3975EMSE 2 DEMO CIRCUIT 1736A DATE: Monday, June 18, 2012 2 SHEET 1 1 OF 1