5 4 3 2 1 D D GND R1 1.0 5% 3 C2 4.7uF 50V 1206 R3 10k RUN JP1 E2 D3 OPT 1 2 1 2 FlipKY-IR05H40CSPTR 3 FlipKY-IR05H40CSPTR L1 4.7uH U1 LT3663EDCB 1 Vin 2 RUN SW 8 BOOST 7 ISENSE 6 VOUT 5 1 7.5V - 36V C1 4.7uF 50V 1206 E1 C D2 OPT NOTE: 60V MAX TRANSIENT VOLTAGE C3 0.1uF 16V 2 HVIN 1 1 R5 71.5k JP3 R4 FB ILIM 3 JP2 0 9 4 0 GND SHDN R2 75k 147k C VLCF5020T-4R7N1R7-1 D1 DFLS240 40V 2.0A C4 47uF 1206 10V 20% E3 R9 20 5% TP1 HVBUCK 3.3V / 5.0V 1.2A TP2 GND R6 255k B E4 B JP4 3.3V 5.0V R7 80.6k 0.6A 0.8A 1.0A 1.2A JP2 0 0 1 1 JP3 0 1 0 1 R8 115k Current Limit Settings Unless noted: Resistors: Ohms 0402 1% 1/16W Capacitors: 0402 10% 25V A 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. CONTRACT NO. APPROVALS DRAWN: J. Drew CHECKED: 4 3 TITLE: SCHEMATIC SIZE DWG NO. APPROVED: ENGINEER: J. Drew DESIGNER: A THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 TECHNOLOGY DATE: 2 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only LT3663EDCB 1.2A, 1.5MHz Step-Down Switching Regulator with Output Current Limit DC1419A Monday, June 30, 2008 REV A SHEET 1 1 OF 1 A