1 A 2 3 4 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 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 Applications Engineering for assistance. 5 REVISION HISTORY ECO REV DESCRIPTION 2 DATE PROTO APPROVED 10/18/05 A T1 5 L1 4.7uH C30 22uF 100V B + C4 100pF R8 47K 0.25W C25 2.2uF 100V 1 -VIN C10 47uF 20V E2 C5 C6 C29 [1] [1] [1] OPT [1] B 5 6 7 8 R2 4.7 4 R7 20 Q1 Si4490DY 1 2 3 2.2nF 8 7 6 5 Q3 [1] 8 7 6 5 Q4 Si7336ADP OPT 4 3 2 1 [1] 3 2 1 R16 169k 1% R18 909 1% R27 [1] Q13 E E R9 0.02 0.5W 11 R28 [1] C CCMP 10nF C13 47pF 0.1uF R22 8 T2 C20 2.2nF 1 C C21 1uF 5 C19 2.2nF B R26 15 C8 0.1uF C23 FMMT618 FMMT718 R4 330 9 13 SFST 12 B SG SGND/PGND VC C17 R13 10K D5 BAT54 4 PA0184 20K C18 10nF OPT R19 100k D SENN 17 OSCAP 7 ENDLY ROCMP 4 3 R20 12k 14 1% SYNC PGDLY R15 3.01k R14 15k 1% 1 16 UVLO TON C12 OPT SENP U1 LT3825EFE 5 15 C Q12 SG 6 C 10 PG 2 VCC FB -VOUT C7 4.7nF 250V D7 4 SG 8 +VOUT [1] E4 C3 R1 0 R3 [1] 1% C2 10 11 12 3 4 0.1uF D2 BAS21LT1 R5 412K 1% 2 E3 C1 56 C11 + R6 1 36V- 72V L2 [1] 7 8 9 6 2 1 2 +VIN E1 [1] D [1] ASSY. VOUT IOUT R3 R28 R27 -A 3.3V 12A -B 5V 8A 28.7K OPT 47 B0540W 470uF 47uF 47uF 42.2K OPT 47 B0540W 470uF 47uF 47uF TBD -C 12V 4A 30.9K 0 OPT OPT 47uF 22uF OPT TBD D7 C29 C1,C2 C5 T1 L2 Q3 PA1477NL 0.1uH Si7336ADP 0.1uH Si7336ADP 1.0uH Si4470EY CONTRACT NO. APPROVALS DRAWN mei DATE TECHNOLOGY 03/17//05 TITLE CHECKED E SCH, LT3825EFE, SYNCHRONOUS FLYBACK CONVERTER APPROVED ENGINEER SIZE DESIGNER 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 CAGE CODE DWG NO REV 2 DC894A Tuesday, January 10, 2006 1 2 3 SCALE: 4 FILENAME: 894A-2.DSN SHEET 5 1 OF 1 E