1 1 R3 * (OPT) RUN JP1 2 SHDN TP3 3 PG 1 4 PG TP2 LT1939EDD 2 SHDN R4 40.2K LDRV 10 A L1 IHLP-2525CZ-ER-6R8 VOUT1 6.8uH D1 B240A COUT1 47uF 10V R10 8.06K 1% R13 OPT TP5 R14 0 R15 1K COUT2 22uF 10V R7 24.9K 1% OPT VIN GND TP6 C7 OPT TP7 VOUT2 [email protected] GND R8 8.06K 1% R11 100K PG [email protected] Q1 ZXTCM322 R16 TP9 VOUT1 C4 OPT VOUT2 SYNC TP4 R9 42.2K 1% C5 OPT LFB 9 13 GND (800kHz) PG 6 RT/SYNC R5 53.6K 1% D3 BAT54XV2T1 D2 OPT C1 0.22uF 7 C2 330pF SW 12 FB 8 3 SS 5 VC C6 OPT C3 0.47uF 16V 2 U1 2 R2 100K 1 R1* (OPT) CIN2 1uF 2 GND 1 OPT CIN1 22uF 50V A R12 BST 11 7V - 25V TP1 D4 OPT 2 1 VIN VIN 1 VIN 2 TP8 B B * DO NOT STUFF R1 WITHOUT R3, SEE QSG FOR DETAILS. 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. 1 CONTRACT NO. APPROVALS DRAWN DATE HELEN 10/18/07 Tiger Zhou 10/18/07 CHECKED APPROVED ENGINEER DESIGNER Monday, November 05, 2007 TECHNOLOGY 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 TITLE LT1939EDD Monolithic Step-Down Switching Regulator with LDO SIZE CAGE CODE SCALE: FILENAME: 2 DWG NO REV A DC1293A SHEET 1 OF 1