5 4 3 2 REVISION HISTORY NOTE: UNLESS OTHERWISE SPECIFIED ECO REV __ 1. ALL RESISTORS ARE 0805. ALL CAPACITORS ARE 0805. D +VIN 1 DESCRIPTION 2 APPROVED PRODUCTION GORAN P. DATE 05-10-10 D R1 OPT. 4 2 1 R2 3.3K E1 VIN 5V - 30V 3 CIN3 CIN2 CIN4 6.8uF 50V XR7 + CIN1 Q1 FZTA42 100uF 35V E2 L1A 4.7uH DRQ127-4R7 R3 38.3K CC1 100pF C D1 PDZ7.5B R4 182 2 CSS 0.1uF 3 1 GND 1 +VIN CDC2 CDC1 6.8uF 50V D2 +VO BAS516 1 2 D3 PDS760 +VO 2 1 3 4 5 SSFLT GATE exposed pad, solder side Ith FB Vcc OC RUN Isense FS SYNC 9 B R7 1K R13 0 8 7 GND 1/2W 2010 C2 OPT, * R11 OPT. CVCC 4.7uF 25V R14 0 E5 PAD B * * TECHNOLOGY JW GORAN P. 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 LOW NOISE SEPIC DC/DC CONVERTER IC NO. LTC3805IMSE-5 DEMO CIRCUIT 1576A N/A THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. SEE QUICK START GUIDE. APPROVALS SIZE 4 16V APXE E4 R10 1K 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. 5 COUT4 +150uF 6 CUSTOMER NOTICE A R8 0.005 COUT3 COUT1 COUT2 33uF 16V XR7 2 2 3 L1B 4.7uH DRQ127-4R7 10 11 R5 113K R6 8.06K R9 12.1K RT 80.6K 4 R12 0 1 +VO Q2 RJK0653DPB U1 LTC3805IMSE-5 RC1 56.2K GND CC2 1nF C +VO 12V / 3A E3 SCALE = NONE 3 DATE: 05-10-2010 2 SHEET 1 1 A REV. 2 OF 1