A B C D E L3 (Opt.) D25 (Opt.) T1 PA0810 L1 0.68uH 4 6 3 10 R4 10 1/4W 1 +VOUT 4 9 E3 3 4 8 1 R54 100 1% R94 147 1% R93 147 1% 2 A 2 3 3 MODE 16 VCC 1 SG FS/SYNC ITH R68 27.4K C75 47pF 2 R46 619 C79 470pF C76 (Opt.) C77 10uF 1 3 2 -VOUT LINEAR TECHNOLOGY CORPORATION Customer Notice R92 47K 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. -VOUT VSB B Q36 MBT3946DW1T1 5 3 Q37 MMBT2907A R69 113K 1 R91 10.0K C8 470pF D6 4.3V MMSZ4687T1 1 C82 75pF R9 (Opt.) 4 LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY C9 0.22uF 2 2 VCC SG R66 100K C10 (Opt.) SS 6 R90 7.50K R7 47K Q34 2N7002 -VOUT FB/PH R41 14.7K -VOUT 4 1 1 11 10 Q27C R89 511 1 10 C78 4.7nF 2 D3 22V MMSZ5251B 12 SS +VOUT VIN 3 2 PGND R63 90.9K C30 2.2nF 250V D29 PT1N4148WS 2 1 1 VCC 5 U2 LTC3726EGN IS+ PT- 13 C7 (Opt.) Q27 FCX491 SG IS- 14 SW 2 PT+ PT5 R61 100 3 1 R56 100 9 8 FG 15 6 4 GND PGND 6 9 2 3 -VOUT C81 10pF R76 680 1206 VSB R83 (Opt.) 5 FS/IN- R87 0 R86 261K R88 47pF C73 470pF GND SSFLT 28.7K VSW Q27C -Vout E4 -VOUT C71 1uF 1 C6 (Opt.) 4 11 ULVO 2 R22 C72 0.1uF FB/IN+ 1 C24 C29 4.7uF 33nF D2 1N4148WS R55 100 1% Q26 FMMT619 2 3 C70 1nF T2 PA0297 47uF 20V 1 Q32 FMMT718 3 2 R84 0 U1 LTC3725EMSE IS 7 NDRV VCC VSLMT 1 C55 470pF GATE 3 2 Rb 162K 8 D28 MMSZ5236BS 7.5V VCC R2 196 1/4W 10K R18 147K D4 4.7V MMSZ5230BS C69 100pF 200V R58 5.1K + C80 C31 (Opt.) 1210 R50 0.012 1W VA R1 196 1/4W C33 22uF 16V Q12 Si7450DP R51 196 1/4W R48 .010 1W 1 Ra C1 390pF 200V 2 3 Q28 FMMT38C Q14 Si7456DP R85 (Opt.) R6 10K CUT 1/4W Q11 (Opt.) C27 2.2nF Q6 MMBFJ201 3 2 C66 2.2nF 100V R3 100 3 VSW 7 R52 196 R49 0 15V/3.3A 2 E2 +Vout L2 12uH R79 3.3K 1 R13 0 1206 1 C5 3.3uF 50V 1210 SLP C4 3.3uF 50V 1210 7 C3 3.3uF 50V 1210 RUN/SS C2 3.3uF 50V 1210 Q8 Si7852DP 2 3 1 5 6 9V-36V -Vin 1 C67 4.7uF 25V VA 11 E1 8 +Vin VIN D1 (Opt.) C D 1630 McCARTHY BLVD. MILPITAS, CA. 95035 408-432-1900 408-434-0507 FAX Title LTC3725EMSE, LTC3726EGN 9V-36Vin Forward Converter Size Document Number Rev Demo Circuit 1174A-C Date: Wednesday, August 12, 2009 Sheet E 1 A of 1 1