5 4 3 2 1 RUN VIN 2 3 Fsw = 430kHz, typical MODE 0 INTVCC 3 1 DCM 2 CCM 3 C 2 R8 0 Ohm 1 JP2 INTVCC R9 OPT ION VIN SGND INTVCC ITH BG MODE PGND VRNG SW PGOOD TRACK/SS U1 LTC3879EUD C6 4.7uF 16V 11 12 14 15 BOOST 16 4 D1 CMDSH-3 13 TG Q2 OPT GND E3 5 Q1 RJK0305DPB INTVCC 10 5 9 VIN- 4 E4 VOUT L1 0.36uH Vishay,IHLP4040DZ-01 E7 Q3 RJK0330DPB R16 0 4 C8 0.1uF 16V VOUT+ VOUT E8 Q4 OPT COUT1 100uF 6.3V 4 COUT2 100uF 6.3V + COUT3 330uF 2.5V + 1.2V@15A COUT4 330uF 2.5V C E10 R11 100K PGOOD D 1 2 3 5 4 R7 20K CIN1 + 180uF 5 R15 C7 220pF 4.5V-14V 1 2 3 INTVCC 6 RUN 1 2 3 R6 18.2K 7 VFB 5 C5 OPT E2 C10 OPT 2 R5 10K 8 1 C4 47pF C11 OPT C3 OPT 16V PGND R3 402K 17 R4 10K C2 10uF 16V C1 1uF 16V JP1 E1 VIN 1 2 3 D ON OFF VIN+ VIN R2 2.2 1 GND VOUT- E11 E5 NOTES: TRACK E6 R13 0 Only apply load from E8 to E10 R14 OPT C9 0.1uF 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. A CONTRACT NO. APPROVALS TITLE: CHECKED: APPROVED: ENGINEER: Mike Sh. DESIGNER: 4 3 SIZE DATE: 2 LTC3879EUD NO RSENSE STEP-DOWN DC/DC CONVERTER A THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 TECHNOLOGY DRAWN: Antonina K 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only DWG NO. REV DC1289A 2 Monday, January 19, 2009 SHEET 1 1 OF 1 A