4 3 C69 5 R88 0 6 4 8 C71 1uF C70 15 PT+ 5 14 PT- * R63 U2 R66 100K VIN R86 C78 33nF C30 opt. 2.2nF 250V -VOUT 2 16 FB/PH C C23 opt. 4 R68 6.2K * R69 C76 opt. C79 2.2nF C75 47pF -VOUT C77 2.2uF VSW C81 Vout/Iout D1 R41 R48 R63 R69 R85 R89 T1 C69 2.5V/20A opt. CMPSH1-4 1.91K 0.039 160K 0 910 PA0865(4:4:1:1) 2.2nF Q34 DC1031A-B 3.3V/20A opt. 2.74K 0.039 160K 0 910 PA0815(6:6:2:1) 2.2nF 2N7002 DC1031A-C 5.0V/20A CMPSH1-4 CMPSH1-4 opt. opt opt 4.42K 0.022 100K 124K 3.01K 536 PA0811(4:4:2:1) 1.5nF 10pF 3 VERSION 1 R46 604 B PT- D29 1N4148W R89 2 * -VOUT For All The Versions C2-C5 1uF,100V TDK C3225X7R2A105M (1210) C31,C33 100uF, 6.3V CER TDK C3225X5R0J107M (1210) C68 Sanyo 6TPE220MI L1 Vishay IHLP-2525CZER1R0M-01 or COOPER HCP0703-1R0-R L2 Coil Tronics HC1-R87 T2 Pulse PA0297 2(1.4mH):1:1 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 CIRUIT 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. 5 -Vout R75 opt. * R41 DC1031A-A D25 - VCC -VOUT 330pF LTC3726EGN Q27 FCX491 1 R83 0 D28 R56 opt. MMBZ5236B 7.5V * 220uF 6.3V opt. E4 3 R85 PT- R61 100 * VERSION TABLE A 3 T2 1 R55 100 1% 220uF 6.3V + C80 E8 SG 1 IS 10 GND PGND R87 0 B C73 0.1uF 470pF 11 C29 33nF 6 1uF FS/IN- 5.1K C72 4 LTC3725EMSE 9 470pF GATE 7 NDRV 3 ULVO 2 SSFLT C24 FB/IN+ U1 VSLMT 1 C55 R84 0 R53 opt. R58 8 VCC R22 15.0K R54 Q25 100 opt. 1% FS/SYNC 3 R77 0 Q33 opt. C31 100uF 6.3V -VOUT Q26 VCC opt. R76 1K 1206 9 R18 365K VCC R29 100K Q28 FDC2512 4 C VA Q32 opt. SLP 6 5 2 1 330pF 0.002 1W IS- 10 1W C27 R52 opt. 1/4W R51 1/4W 2.4 * R48 321 R50 321 RUN/SS 100 VA 4 VA IS+ 11 123 R3 4 + C68 5 * 50V C33 100uF 6.3V R2 1.2 1/4W C67 4.7uF 25V * D1 8765 VSW D VCC C66 1nF 200V 4 0 E2 8765 6 R49 -Vin 7 ITH 2 5678 12 C5 1.0uF 100V SW C4 1.0uF 100V +Vout E3 * D25 Q12 Si7336ADP R79 510 Q14 Si7336ADP PGND C3 1.0uF 100V C2 1.0uF 100V 8 FG 2 36-72Vin 3 4 Q11 Q8 Si7450DP opt. E7 0.87uH 10 9 13 D + +VOUT L2 11 7 1.0uH 1 MODE 3 5 GND E1 * T1 VIN L1 +Vin 2 8 5 4 3 CONTRACT NO. APPROVALS DRAWN DATE J. WU 12/5/05 CHECKED A TITLE LTC3725EMSE, LTC3726EGN, 36V - 72Vin Forward Converter APPROVED ENGINEER TECHNOLOGY 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 K. Mathews 12/5/05 DESIGNER Monday, August 28, 2006 2 SIZE CAGE CODE SCALE: FILENAME: DWG NO REV DC1031A SHEET 1 A 1 OF 1