5 4 3 2 1 VIN VIN+ RUN D ON Fsw = 300kHz, typical R1 OPT 1 R16 OPT 3 JP1 C4 47pF 2 CCM INTVCC 3 4 3 JP2 R8 0 R15 0 2 1 INTVCC R9 OPT R11 100K PGOOD SGND INTVCC ITH BG MODE PGND VRNG SW PGOOD TRACK/SS U1 LTC3879EMSE TG BOOST E4 INTVCC 11 12 Q2 OPT 5 10 VINQ1 BSC093N04LSG 4 4 C6 4.7uF 16V 1 2 3 5 VIN C1 0.1uF 50V D1 SD103AWS 13 14 VOUT L1 0.72uH Worth 744325072 E7 15 Q3 BSC035N04LSG 16 R17 0 4 C8 0.1uF 50V Q4 OPT COUT3 COUT1 47uF 6.3V 4 C VOUT+ VOUT E8 5 R7 10K ION 9 COUT2 47uF 6.3V 1.2V@12A COUT4 + 330uF 2.5V 2R5TPE330M9 + 330uF 2.5V 2R5TPE330M9 1 2 3 6 1 DCM 7 RUN 5 C3 OPT VFB 1 2 3 C5 OPT 1 GND 5 C E2 4.5V - 34V CIN1 + 100uF 50V SANYO, 50ME100PX 2 CIN2 10uF 35V E3 1 2 3 INTVCC MODE CIN3 10uF 35V 1 8 R5 10K CIN4 10uF 35V R2 2.2 R3 576K 2 C7 470pF GND R4 10K CIN5 OPT C10 OPT VIN 17 R6 20K D VIN 2 OFF E1 VIN E10 GND VOUT- E11 E5 TRACK NOTE: E6 R13 0 B R14 OPT Only apply load from E8 to E10. C9 0.1uF 50V 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. A CONTRACT NO. APPROVALS TITLE: CHECKED: APPROVED: ENGINEER: Mike Sh. DESIGNER: 4 3 SIZE A THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 TECHNOLOGY DRAWN: Antonina K DATE: 2 B 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only LTC3879EMSE NO RSENSE STEP-DOWN DC/DC CONVERTER DWG NO. REV DC1345A 2 Monday, August 03, 2009 SHEET 1 1 OF 1 A