REVISION HISTORY ECO REV 0 - +VIN 18V - 72V CIN1 2.2uF 100V R1 221K 1% 0805 CIN2 2.2uF 100V E1 Q1 MMBTA42LT1G -VIN D3 CO1 100uF 6.3V BAS516 R4 22 0805 1206 VU1 R5 681 1% 1206 CO2 100uF 6.3V CO3 100uF 6.3V E4 D1 7 8 1 1 3 GND 2 PDS1040 R22 0 Ohm D6 BAS516 C2 1uF +VOUT C11 (Opt) C10 (Opt) 1 1 R18 221K 1% 0805 R17 3 JP1 3 0 Ohm 2 OFF 4 R19 15.8K 1% GATE 10 C3 2 ON SSFLT 0.1uF R10 C12 (Opt) 75K 5 ITH Vcc FB OC RUN ISENSE FS SYNC ITH 9 8 7 6 1uF R7 R2 R23 0 Ohm GND 11 3 VCC VIN OPTO GND COMP OC FB C14 (Opt) 6 R12 6.8K R13 C5 10K 0.01uF 5 4 C7 0.33uF R14 22.1K 1% R11 270 D4 BAS516 4 1 (Opt) 3.01K 1% 2 C4 1uF Q2 FDC2512 C9 +VIN 1 C1 150pF 200V U1 [1] R9 (Opt) U2 LT4430ES6 D7 BAT760-7 R3 68 1206 R15 100K C6 100pF R16 10 ITH +VOUT 3.3V @ 3A CO4 100uF 6.3V 2 R21 VCC D2 PDZ6.8B 5 6 3 [1] APPROVED <APPROVED> +VOUT 4 RUN DATE <DATE> 1st PROTOTYPE TR1 PA1277NL +VIN E2 E3 DESCRIPTION ISO1 PS2801-1-K RCS 0.040 1% 3 2 D5 BAS516 C15 VU1 2200pF 250V R6 (Opt) R20 (Opt) 1206 C16 E5 FSET (Opt) 1206 SYNC 1 EXT [1] ASSY 2 3 INT JP2 C8 1000pF R8 1M 100k -B LTC3805EMSE-5 DNP DRAWN: Rudy Bautista ENGINEER: R21 LTC3805EMSE APPROVALS This circuit is proprietary to Linear Technology and supplied for use with Linear Technology parts. Customer Notice: Linear Technology has made a best effort to design a circuit that meets customer-supplied specifications; however, it remains the customers 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 Applications Engineering for assistance. U1(IC) -A Victor Khasiev LINEAR TECHNOLOGY CORPORATION 1630 McCARTHY BLVD MILPITAS, CA. 95035 (408)432-1900 (408)434-0507 (FAX) www.linear.com LTC Confidential For Customer Use Only Title APPROVED: CHECKED: Date: Wednesday, April 16, 2008 18V - 72Vin to 3.3Vout @3A Isolated DC/DC Converter SD Document Number Rev Demo Circuit 1311A C:\ORCADWIN\CAPTURE\1311A\1311A_REV2.DSN Sheet 2 1 of 1