5 +VIN 4 3 2 E3 1 L1 3.3uH PQI2050-3R3 SW1 36V - 72V T1 G45R2-0209 J1 4.7uF 100V CIN1 CIN2 CIN3 1210 14.7K 14 6 SYNC 26 2 38 39 PGND PGND 1 36 34 TOS AOUT TBLNK SOUT SYNC INTVCC RT INTVCC ISENSEN 3 E2 NC TAS C2 4.7uF 25V 0805 COMP R21 1K RCS1 0.012 0815 15 32 J4 5.1 1206 30 C12 0.1uF 5 C R18 100K D5 BAS516 C5 22pF R1 1uF 30.1K C3 22nF R10 OPT R29 100 0805 INTVCC R15 1K R23 100 U2 PS2801-1 C13 1uF R19 100K 4 1 3 2 C18 4.7nF C22 22uF 10V 0805 D4 BZT52C4V3 +VO1 C20 R16 34.8K 3 V+ 1 NOTE: UNLESS OTHERWISE SPECIFIED: ALL RESISTORS & CAPACITORS ARE 0603 . ALL RESISTORS ARE 1% MULTILAYER RESISTORS. ALL CERAMIC CAPACITORS ARE X7R REF RTOP 8 RMID GND-F GND-S 6 5 4 R28 137K 7 T1(OPT 2) PA2720NL 6 7 SW1 8 9 10 SW2 1630 McCarthy Blvd. Milpitas, CA 95035 CUSTOMER NOTICE LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A Phone: (408)432-1900 www.linear.com CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; TECHNOLOGY Fax: (408)434-0507 HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO LTC Confidential-For Customer Use Only VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL TITLE: SCHEMATIC APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT 48VIN TO 5V, 20A ISOLATED DC/DC CONVERTER IN 1/8 BRICK PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 R20 137K 2 COMP COLLECTOR U3 LT1431CS8 EVAL1: EFE PACKAGE (FE38 (31) ) BOARD SIZE: 2.30 BY 1.45 B +VO1 1uF C21 3.3nF 5 -VOUT E6 B A D Q3 BSC0902NSI R24 1K 4 1 CSYS 560uF 10V +VO1 250V 1812 T1-5 + R25 10K E1 2 CO2 1210 OPT C1 CY1 2200pF T1-2 5V / 20A Q2 IRF6217 20 SGND GND +VOUT 16 FB R2 NC TAO 22 21 SW2 C15 0.22uF 1210 250V R26 200 0805 C14 68nF 1206 250V CO1 47uF 10V 1210 5.1 0805 R32 24 4 13 IVSEC PGND 12 ISENSEP 19 44.2K 11 LT3753EFE OVLO SS2 R5 8 17 57.6K OUT U1 GND 10 R6 5 Q1 BSC190N15NS3 G OC UVLO_VSEC 18 9 1.87K SS1 1.96K R7 NC R8 TEST1 0805 TEST2 VIN R9 105K NC 28 E4 37 C4 1uF 100V 0805 E5 J3 Q4 BSC0902NSI R33 2 11 T1-5 J2 C 8 T1-2 R17 15 7 -VIN + NC C31 33uF 100V (OPT) D +VO1 4 3 2 N/A DATE: IC NO. REV. LT3753EFE DEMO CIRCUIT 2050A SHEET Monday, March 17, 2014 1 3 1 OF 1 A