A B C D E L3 (Opt.) 1 3 2 (Opt.) VIN VSW R95 0 R23 R24 (Opt.) 1/4W C66 3.3nF 100V Q2 1 C1 1.5nF 100V 1206 -VOUTP1 3 Q27C 4 SG C82 82pF R94 147 Q37 MMBT2907A VSB 3 3 MODE IS+ 7 SLP RUN/SS 6 PGND 16 11 10 12 SW IS- R66 100K +VOUT R41 11.8K C10 (Opt.) 4 R9 (Opt.) R69 0 C75 68pF 2 R46 619 R68 19.6K C79 2.2nF C76 (Opt.) -VOUTS C77 22uF 1210 -VOUTP -VOUTS 3 LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY LINEAR TECHNOLOGY CORPORATION 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. 47K -VOUTS B FB/PH Customer Notice R92 VCC 2 1 1% SG Q36 MBT3946DW1T1 5 C8 470pF D6 4.3V MMSZ4687T1 C9 0.22uF 3 Q27 FCX491A -VOUTS 2 R93 147 1% -VOUTS A 1 Q34 2N7002 2 2 VCC R91 10.0K 3 2 R7 47K -VOUTP SS R90 7.50K 1 R89 715 1 1 -VOUTS -VOUTP -VOUTP 3 D3 22V MMSZ5251BS 13 C78 4.7nF C30 2.2nF 250V VIN D29 PT1N4148WS 2 GND SS 6 C81 10pF 2 1 1 VSW PT- R63 90.9K 47pF D2 1N4148WS 14 U2 LTC3726EGN C7 100pF 11 R86 261K PT+ PT5 R87 0 C88 2 8 FG 15 6 4 R61 100 -Vout 1 R56 100 C70 3.9nF 8 10 7 IS GATE 3 C73 470pF E4 C71 1uF 5 FS/IN- 6 9 T2 PA0297 68uF 16V 1 SSFLT C6 100pF 4 GND 2 C29 33nF PGND ULVO VSLMT 1 C24 4.7uF C55 4.7nF 1 5.1K C72 0.1uF FB/IN+ VCC R58 U1 LTC3725EMSE 1 2 2 3 8 D4 4.7V MMSZ5230BS R22 28.7K NDRV VCp R18 147K 1 R83 (Opt.) R84 0 C80 + C83 VSB FS/SYNC 10K Rb 162K R76 470 1206 R85 (Opt.) C27 2.2nF 2 Ra 10K R55 100 1% 9 R6 1 2 3 CUT Q28 FMMT38C R54 100 1% D28 MMSZ5236BS 7.5V VCC Q26 FMMT619 Q27C 2 3 Q32 FMMT718 3 2 R98 22 1 Q6 MMBFJ201 3 C31 C33 22uF 16V 1210 C69 220pF 200V 1206 R50 0.005 1W VA C20 (Opt.) 200V FMMT718 3 Q3 Q12 Q38 Si7450DP Q14 Q15 Si7852DP 2 Q8 Q11 Q39 Si7370DP 2 3 7 C89 0.22uF R49 R3 100 3 4 E3 10uH PULSE, PA2050.103NL R1 R2 R51 R52 75 8 Q1 FMMT619 1 R11 R12 R79 3.3K 2 9 VCp 4 +Vout 12V/8.4A 1 2.2K D7 BAS21 1.0 10 R13 0 1206 1 R97 +VOUT L2 1 5 VCC E2 1 1 -Vin 2 3 11 T3 PA1005.100 3 3 SG C3 C4 C5 6.8uF 50V 1812 C2 6.8uF 50V 1812 1 ITH E1 R4 10 25V 6 7 4 6 5 8 VA 2 VIN C67 4.7uF D1 (Opt.) 5 4 +Vin 9V - 36V D25 (Opt.) T1 PA0910 1 L1 0.47uH 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 1300A-B Date: Friday, June 05, 2009 Sheet E 2 of 3 1