5 4 3 2 1 REVISION HISTORY ECO REV 1 DESCRIPTION 2 APPROVED DATE JIAN L. 11-16-09 PRODUCTION 1 VIN D D2 BAS16HT1 (OPT) SOD-323 2 R1 (OPT) E1 VIN R11 (OPT) VIN 1 11 R5 20K C6 1nF R6 R10 42.2K 7 BOOST FB VIN SENSE- INTVCC SENSE+ BG GND 4 R3 10 9 5 6 7 8 C4 0.1uF 50V 0 R4 VIN 4.7 8 C10 4.7uF 16V CIN1 100uF 50V GND VIN- E6 1uH RS1 C 0.002 R9 49.9 E8 Q4 (OPT) COUT1 + COUT2 + 220uF 47uF 4V 6.3V 4 R7 (OPT) Q2 BSC035N04LSG VOUT+ E7 PG0006 102NL INTVCC D1 SD103AWS CIN5 (OPT) + E4 L1 4 C8 0.1uF 50V 13 C9 (OPT) (OPT) 12 ITH CIN4 4.7uF 50V 5 6 7 8 2 CIN3 4.7uF 50V R13 49.9 VOUT 2.5V@12A COUT3 COUT4 220uF (OPT) 4V 1206 E9 1 2 3 4.7nF 6 CIN2 4.7uF 50V Q3 (OPT) 1 2 3 5.1K C3 C 4 5 6 7 8 R2 SW 5 1 2 3 470pF TG RUN/SS 1 C2 3 BSC093N04LSG 4 2 C1 0.1uF 50V 3 OFF Q1 VIN 4.5V - 34V E3 1 2 3 LTC3854EMSE 2 5 6 7 8 U1 1 JP1 RUN ON C11 (OPT) VIN+ E2 GND RUN/SS D R8 (OPT) E10 GND VOUT- R12 0 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 APPROVALS PCB DES. HZ JIAN L. APP ENG. TECHNOLOGY TITLE: SCHEMATIC HIGH EFFICIENCF STEP-DOWN CONVERTER SIZE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 4 3 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only N/A SCALE = NONE 2 IC NO. REV. LTC3854EMSE 2 DEMO CIRCUIT 1487A DATE: Monday, February 22, 2010 SHEET 1 1 OF 1 A