A B C D E L3 470uH L1 0.68uH 4 3 3 C67 4.7uF 25V VA R4 (Opt.) 1 +VOUT 4 11 10 9 E3 3 4 R54 100 1% 1 R55 100 1% Q26 FMMT619 2 3 Q27C R76 470 1206 U2 LTC3726EGN SS C78 4.7nF C30 2.2nF 250V 2 3 FS/SYNC R66 100K 3 +VOUT MODE 16 SG VCC 1 11 10 R41 4.53K C10 680pF R9 100 4 ITH 12 PGND R63 90.9K VIN VCC 5 GND C7 (Opt.) Q27 FCX491 FB/PH 9 PT- IS+ 14 IS- PT+ PT5 R61 100 3 1 R56 100 SG SLP 8 SW 15 6 4 5 FS/IN- R87 0 R86 261K 2 10 IS C73 470pF 11 VSLMT 9 R88 47pF 3 1 C6 (Opt.) -Vout E4 -VOUT C71 1uF 13 SSFLT PGND ULVO 2 C24 C29 4.7uF 33nF C72 0.1uF 4 R83 (Opt.) C70 1nF T2 PA0297 220uF 6.3V VSB R84 0 U1 LTC3725EMSE FB/IN+ 1 R22 28.7K 2 7 NDRV VCC 6 1 C55 470pF GATE 3 2 Rb 162K R18 147K 8 Q32 FMMT718 3 2 R58 5.1K 10K D4 4.7V MMSZ5230BS D28 MMSZ5236BS 7.5V VCC R2 28.7 1/4W 1 Ra C69 470pF 200V R1 28.7 1/4W + C80 C31 (Opt.) 1210 R50 0.004 1W VA R51 28.7 1/4W R48 .010 1W C33 100uF 6.3V Q12 Si7852DP FG Q28 FMMT38C C1 1nF 100V R85 (Opt.) R6 10K CUT R52 28.7 1/4W Q14 HA2169H 2 3 Q6 MMBFJ201 3 2 Q11 (Opt.) C27 2.2nF 3 VSW 7 C66 3.3nF 100V R3 100 5V/10A 1 R49 0 L2 4.3uH R79 1.0K 8 E2 +Vout 2 R13 (Opt.) 1206 1 C5 3.3uF 50V 1210 7 C4 3.3uF 50V 1210 RUN/SS C3 3.3uF 50V 1210 6 C2 3.3uF 50V 1210 1 5 1 E1 Q8 Si7852DP 2 D1 BAS21 1 GND -Vin VIN 8 +Vin 9V-36V D25 BAS21 T1 PA0801.005 6 R69 0 C75 47pF 2 R46 619 R68 12.1K C79 1.0nF C76 (Opt.) C77 10uF -VOUT -VOUT D29 PT1N4148WS Q27C R89 158 2 C9 0.22uF -VOUT R94 147 1% SG R93 147 1% 2 A VSB B LINEAR TECHNOLOGY CORPORATION 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. This Circuit Is Proprietary To Linear Technology And Supplied For Use With Linear Technology Parts. R92 47K -VOUT 3 Q37 MMBT2907A LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY -VOUT 1 C82 75pF Q36 MBT3946DW1T1 5 C8 470pF D6 4.3V MMSZ4687T1 6 R91 10.0K 1 VCC Q34 2N7002 2 2 1 1 SS 1 R7 47K 2 D3 12V MMSZ5242BS R90 7.50K 1 3 2 4 C81 10pF 2 1 1 VSW 3 D2 1N4148WS 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-A Date: Friday, August 14, 2009 Sheet E 1 A of 1 1