1 2 3 4 5 REVISION HISTORY ECO REV DESCRIPTION DATE APPROVED 1 PRODUCTION 06/03/11 KURK M. T1 5 [1] +VIN E1 6 2 1 L1 L2 [1] 7 8 9 A E3 C1 C2 C5 C6 C29 [1] [1] [1] OPT [1] +VOUT A [1] 4.7uH 36V- 72V C30 22uF 100V + C4 100pF R8 47K 0.25W C25 2.2uF 100V -VIN R11 [1] C11 + 0.1uF 5 6 7 8 R1 0 B R3 [1] 1% R10 [1] E4 C3 D2 BAS21LT1 R5 412K 1% 3 4 R6 [1] C10 47uF 20V E2 10 11 12 R2 [1] 4 R7 [1] Q1 [1] 1 2 3 [1] 8 7 6 5 Q3 [1] 8 7 6 5 Q4 Si7336ADP OPT 4 D7 4 3 2 1 3 2 1 R27 [1] R18 [1] 1% SENN SGND/PGND 12 R9 E FMMT718 [1] 11 C 9 CCMP 8 C23 C17 C18 C13 47pF 10nF OPT 0.1uF R26 15 C8 0.1uF [1] 1 [1] 1uF 5 C20 2.2nF [1] C21 C T2 C19 R22 FMMT618 R4 330 0.5W 13 SFST VC 6 OSCAP E R28 [1] B SENP 17 7 Q13 B SG PG ENDLY ROCMP 4 3 R16 169k 1% 14 1% R20 12k 1 16 2 VCC R15 3.01k R14 15k 1% OPT TON C12 C PGDLY SYNC 15 C Q12 SG U1 LT3825EFE UVLO 5 10 FB B [1] SG 8 -VOUT C7 4.7nF 250V 4 R13 10K D5 BAT54 PA0184 R19 100k [1] ASSY. VOUT IOUT R2 R6 R7 R9 -A 3.3V 12A 4.7 28.7K 110 39 -B 5V 8A 4.7 29.4K 150 -C 12V 5A 15 R3 R10 R11 R18 R22 R28 R27 0.02 39 110 909 20K OPT 47 20 0.012 OPT 150 787 2K OPT 47 68 0.012 OPT 160 1.5K 7.5K D7 C5 C19 C23 C29 2.2nF 47uF 2.2nF 10nF 47uF 2.2nF 47uF 220pF 22uF 470pF OPT 330pF C1,C2 C3 B0540W 47uF B0540W OPT Q3 T1 L2 470uF PA1477NL 0.1uH Si4490DY Si7336ADP 2.2nF 470uF PA1735NL 0.1uH Si4490DY Si7336ADP 3.3nF 150uF PA1736NL 1.0uH Si7450DP Si4470EY Q1 D D 30.9K 160 0 OPT 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. E THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 1 2 3 APPROVALS PCB DES. APP ENG. TECHNOLOGY MI KURK M. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only E TITLE: SCHEMATIC SYNCHRONOUS FLYBACK CONVERTER SIZE N/A SCALE = NONE 4 IC NO. LT3825EFE REV. DEMO CIRCUIT 894B DATE: Monday, August 15, 2011 SHEET 1 5 1 OF 1