5 4 3 2 1 REVISION HISTORY ECO REV - 1 2 APPROVED DESCRIPTION PRODUCTION ADD "C11" DATE MOLLY Z YING C. 01-13-11 02- 08-11 D D E1 VIN 4.5V - 36V 60V TRANSIENT E2 R2 GND S 12 UVLO 17 EN BOOST 22 SW SW SW SW SW SW SW SW SW 1 2 3 4 23 24 25 26 27 PG 18 (OPT) C ENABLE 1 EN U1 2 DIS C11 2.2uF 10V C3 47uF 6.3V 1210 L1 3.3uH 19 R1 0 Ohm BIAS E4 C1 22uF 63V (OPT) VIN VIN VIN + C2 10uF 50V 1210 13 14 15 VIN E3 GND C4 0.68uF 10V 0603 C R3 100K E5 PG LT3690EUFE 3 JP1 C7 680pF FB 9 8 RT 7 R5 VC SYNC 5 45.3K 1% 450kHz C8 0.47uF 10V 0603 VCCINT SYNC R6 102K 1% S 1 MODE S GND 20 C10 (OPT) 28 B E6 SS GND GND GND GND C6 (OPT) R7 21.5K 1% R4 316K 1% C9 (OPT) 11 6 10 16 21 C5 1000pF VOUT 3.3V @ 4A 2 FIXED FREQ 3 BURST MODE B JP2 S S CUSTOMER NOTICE APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. A MOLLY Z 5 4 3 36V / 4A mPOWER SYNCHRONOUS BUCK REGULATOR N/A SCALE = NONE A LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY TITLE: SCHEMATIC SIZE C:\PADS PROJECTS\1520A\SCH\1520A_REV2.DSN THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. TECHNOLOGY RB 1630 McCarthy Blvd. Milpitas, CA 95035 www.linear.com Phone: (408)432-1900 Fax: (408)434-0507 DATE: 2 IC NO. REV. LT3690EUFE DEMO CIRCUIT 1520A Monday, March 28, 2011 2 SHEET 1 1 OF 1