5 4 3 2 1 REVISION HISTORY IntVcc MODE CLKOUT PHASE 3 CCM BURST D o 4 o 3 2 120 1 180 90 PLLIN/MODE DESCRIPTION APPROVED DATE JOHAN S. 01-11-10 PRODUCTION R24 200K D 1 JP3 E3 VOUT 1 2 o JP2 REV __ PGOOD R19 100K IntVcc 4 DCM ECO E2 3 2 C6 3 SS R3 68.1K JP5 11 BG 14 R14 0 8 0 R2 215K R10 optional C9 39pF C23 4.7uF 10V B VOUT R11 (optional) 0805 Q2 Si4840DY 4 D2 CMDSH-4E C5 1nF R1 12mOhm 1% 0.5W L1 3.2uH C4 0.1uF C C10 (optional) VOUT E8 IntVcc E6 GND 12 C24 opt R9 TRACK 4V to 36V E7 C22 22uF/50V E10 5 6 7 8 PGOOD Vin 18 20 Phasmd 19 PLLIN/MODE 15 LTC3835EFE 6 1 VFB U1 1200pF 2 TRACK C7 150pF SGND TRACK/SS Ith 5 C13 10uF/50V 4 Sense+ 9.53K 1% C8 0.1uF Boost 3 13 17 R4 TRACK/SS TG Q1 Si4840DY 21 0 4 Vin C12 0.1uF/50V SW Sense- R13 Plllpf 16 JP1 2 IntVcc 4 CLKOUT EXTVCC 250kHz 1 9 3 R20 10K 10 2 550kHz 1000pF C16 100pF RUN IntVcc 1 400kHz R6 10K PGND FREQUENCY C E11 C15 SGND JP4 VIN R5 0 IntVcc 5 6 7 8 CLKOUT 1 2 3 1 7 OFF D1 (OPT) C14 (optional) C2 4.7uF 16V GND R21 0 C3 4.7uF 10V 3.3V@5A C1 150uF/10V 1 2 3 ON E9 C17 1uF B R17 0 R18 0 R23 SGND (optional) E4 EXTVCC EXTVCC E5 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 NOTES: UNLESS OTHERWISE SPECIFIED, THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 4 3 APPROVALS PCB DES. APP ENG. TECHNOLOGY A.K. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only TITLE: SCHEMATIC JOHAN S. SINGLE 5A HIGH FREQUENCY STEP-DOWN DC/DC CONVERTER SIZE N/A SCALE = NONE DATE: 2 IC NO. LTC3835EFE REV. 1 DEMO CIRCUIT 967B Friday, January 08, 2010 SHEET 1 1 OF 1 A