5 4 3 2 1 REVISION HISTORY ECO REV DESCRIPTION PRODUCTION 2 APPROVED DATE CHARLIE Z. 12-13-13 D D VIN U1 LTC3638EMSE VIN 4V - 140V E1 + C1 22uF 200V R1 2M JP3 RUN 1 ON R2 OPT 3 C2 1uF 200V 2220 2 14 OFF GND L1 VIN SW VFB RUN 1 D1 SBR1U200P1 12 VPRG1 OVLO 1 7 R4 OPT C3 OPT SS C9 0.1uF VOUT 1.8V / 3.3V / 5V 250mA GND E3 C 1 2 6 JP2 * * 10 GND NC NC NC NC OPT E5 2 4 13 15 FBO ISET E2 B A C4 47nF 17 11 VIN FBO GND GND R8 VPRG2 8 16 5 * 2 3 R3 0 JP1 R7 OPT C6 C7 100uF 10V 1210 9 3 E4 R6 0 B A 3 C 150uH CDRH105R VOUT C8 C10 OPT 1210 VOUT JP1 JP2 1.8V B B 3.3V A B 5.0V B A EXT. R A A B B NOTE: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE 0603. ALL CAPACITORS ARE 0603. 2. FOR 5V OUTPUT, VIN RANGE IS 6V-140V. 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. A TECHNOLOGY LT CHARLIE Z. TITLE: SCHEMATIC 5 4 3 LTC3638EMSE DEMO CIRCUIT 2057A IC NO. N/A SCALE = NONE A HIGH EFFICIENCY, HIGH VIN, 250mA STEP-DOWN CONVERTER 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 DATE: Friday, December 13, 2013 2 REV. 2 SHEET 1 1 OF 1