1 2 RUN JP1 1 3 OFF ON 2 R14 100K C21 3.3V A E2 3.3V C14 1uF 50V 0.1uF 50V C13 22uF 50V U1 LT3681EDE R10 100K PGOOD VIN 3.3V R9 165K R6 102K R11 12.7K C17 1000pF 1 PGOOD 2 BIAS 3 FB 4 GND 5 VC 6 RT R7 105K E1 VIN 4.5V-34V 3.3V SD 14 VIN 13 SW 12 C10 BOOST 11 BD 10 7 GND A GND E4 L1 0.47uF 4.7uH C15 22uF 10V PDC 9 PDA 8 C20 1uF E3 VOUT 3.3V@2A E5 GND B B 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 11/20/06 WEI GU 11/20/06 CHECKED TECHNOLOGY TITLE APPROVED ENGINEER DESIGNER Friday, May 18, 2007 LT3681EDE STEP-DOWN REGULATOR SIZE CAGE CODE SCALE: 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 DWG NO FILENAME: 2 REV A DC1122A SHEET 1 OF 1