5 4 D 3 2 VIN R2 R1 10K opt. 10K opt. VIN U1 LTC3772EDDB JP1 1.8V ADJ1 2 3 ITH/RUN SW 6 2 VFB VIN 7 1 GND PGATE 8 3 3.3V 5 4 6 Rf1 82.5K 174K C 4.7uH Cf1 E3 L2 22pF 1.0uH D2 MBRD835L opt. D1 B220A 1 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. THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 Q3 NTMS5P02R2 opt. L1 Rf4 56.2K A 4 Q2 NTMS5P02R2 opt. 5 6 7 8 Rf3 4 2.5V 4 Q1 FDC638P Rf2 140K 3 1 2 3 N/C GND 5 6 7 8 680pF 20K IPRG D E2 4 Cout1 47uF 6.3V opt. Cout2 100uF 6.3V opt. Cout3 100uF 6.3V opt. C3 1uF 6.3V opt. CONTRACT NO. APPROVALS DRAWN June Wu DATE 9/9/04 CHECKED TECHNOLOGY B 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC3772EDDB, 550kHz Step-Down DC/DC Converter Walker Bai 9/9/04 DESIGNER Monday, February 28, 2005 3 GND TITLE APPROVED ENGINEER VOUT 1.8V/2.5V/3.3V @2A C4 opt. E4 3 Rc1 5 E1 + C2 47uF 10V opt. 1 2 5 6 C Cc1 4 Cin3 47uF 10V opt. VIN 2.75V-8V 4 opt. 1 2 3 Cc2 Cin2 47uF 10V opt. Cin1 22uF 10V ITH/RUN E6 1 SIZE CAGE CODE SCALE: DWG NO FILENAME: 2 A REV A DC836A SHEET 1 1 OF 1