T1 PA1277NL E3 R1 220k 1206 Q1 MMBTA42 3 Cin1 2.2uF 100V 1 D2 PDZ6.8B R2 100k 1206 4 5 6 3 7 8 E1 Co1 100uF 6.3V D1 R3 68 1206 Co2 100uF 6.3V Co3 100uF 6.3V Co4 100uF 6.3V opt. E4 PDS1040 +Vout 3.3V, 3A GND D6 BAS516 C1 150pF Vcc U1 LTC3803ES6-3 1 Ith/Run R10 80.6k R6 opt. Vu1 Q2 FDC2512 1 2 5 6 Ith G 6 2 GND Vin 5 3 Vfb=0.8V Sns 4 Vcc 3 D3 R4 22 BAS516 2 1 C2 0.1uF R7 4.7k C3 0.1uF 10V R16 10 Vu1 R5 680 4 -Vin E2 2 +Vin 18V to 72V +Vout Rcs 0.040 1206 +Vout R9 opt. 1206 D7 BAT760 +Vout Vcc Ith D4 BAS516 R11 R12 6.8k 4 U3 3 1 2 270 U2 C4 0.1uF 1 VIN OPTO 6 2 GND COMP 5 C7 0.33uF PS2801-1 3 OC D5 BAS516 FB 4 LT4430ES6 +Vout C5 R13 C6 2.2nF 56k 47pF R15 R14 22.1k 100k C8 2200pF 250V 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. CONTRACT NO. APPROVALS DRAWN June Wu DATE 4/27/06 CHECKED TECHNOLOGY TITLE LTC3803ES6-3 18V-72Vin to 3.3Vout@3A Isolated DC/DC Converter APPROVED ENGINEER Goran Perica 4/27/06 DESIGNER Tuesday, November 07,2006 SIZE 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 CAGE CODE SCALE: FILENAME: DWG NO REV DC1100A SHEET A 1 OF 1