5 4 3 2 1 C1 100pF R1 21.5K Vin + 4 E1 -VIN R3 221K R4 221K 3 CIN2 2.2uF 100V 1 D2 PDZ6.8B 6.8V 1 R6 51 2 COUT1 100uF 6.3V D1 UPS840 10 9 1 5 D3 BAS516 +Vout 7 8 D4 OPT 2 3 4 VFB GND R12 0.068 7 VIN 6 NGATE 5 R8 220 R13 OPT R17 OPT C12 0.1uF COMP 5 OC 0.6V FB 4 C6 OPT C5 OPT U2 LT4430ES6 C8 OPT OPT C7 OPT R14 OPT R15 OPT R19 0 CUSTOMER NOTICE NOTES: 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. INSTALL 2200pF/250VAC CAPACITOR IN PLACE OF RESISTOR R19 IN ISOLATED APPLICATIONS THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 GND 3 C4 OPT U3 OPT D6 OPT 3 JP1 2 R11 OPT B 2 OFF 6 D5 OPT C10 4.7uF 1 ON OPTO 1 RUN VIN 1 R16 12.1K R18 15K 1 2 C11 47pF LTC3873ETS8 ITH RUN/SS R10 0 8 4 B SW 3 C9 2.2nF IPRG C C3 OPT 2 1 4 R9 0 A C2 150pF 200V 3 U1 3.3V@3A 3 Q2 FDC2512 E2 2 R5 OPT 1 2 5 6 R7 OPT +VOUT COUT3 100uF 6.3V -VOUT Q1 MMBTA42 C COUT2 100uF 6.3V E3 2 E4 2 _ CIN1 2.2uF 100V 1 36V-72V D +VOUT 1 +VIN R2 0 T1 PA1861_RevS01A 2 D 4 3 CONTRACT NO. APPROVALS DATE DRAWN Antonina Karpova 10/04/06 CHECKED TECHNOLOGY TITLE APPROVED ENGINEER Victor Khasiev 10/04/06 DESIGNER Monday, February 26, 2007 SIZE A LTC3873ETS8 TELECOM DC/DC CONVERTER CAGE CODE SCALE: 2 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 FILENAME: DWG NO REV DC1154A SHEET 1 2 1 OF 1