5 4 3 2 1 SUMIDA CDRH8D43-6R8 L1 6.8UH D D U1 LT3680EMSE GND 4 + C2 C3 4.7UF,50V 1210 22UF,50V E8 SANYO 50CE22BS 5 BD BOOST VIN RUN/SS JP1 R2 110K FB 8 PGOOD 7 SW E2 RUN SHDN EXTSS EXTSS 2 R1 63.4K RT 10 VC 9 R3 590K SYNC 6 1 2 3 4 C4 47UF,10V 1206 VOUT [email protected] C5 0.1UF 50V 0603 E6 GND E7 R5 15K C8 100PF E3 C7 0.22UF,50V 0805 PGOOD GND JP2 BURST MODE SYNC ON 1 2 3 E9 SYNC B B CUSTOMER NOTICE NOTES: UNLESS OTHERWISE SPECIFIED 1. ALL RESISTORS ARE IN OHMS, 0402. ALL CAPACITORS ARE IN MICROFARADS, 0402. A C C6 1000PF R6 100K E4 E5 R4 100K 11 C 1 3 VIN E1 6.3V - 36V GND C1 0.47UF GND D1 MBRA340T3 2 1 2. INSTALL SHUNT ON JP1 AND JP2 PINS 1&2. CONTRACT NO. 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 4 3 APPROVALS DRAWN: TECHNOLOGY KIM T. CHECKED: TITLE: SCHEMATIC SIZE DWG NO. APPROVED: ENGINEER: KEVIN H. DESIGNER: A DATE: 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only A 3.5A, 36V STEP-DOWN SWITCHING REGULATOR WITH SYNC FUNCTION DC1149A * LT3680EMSE Thursday, August 09, 2007 2 SHEET 1 REV A 1 OF 1