5 4 3 2 U1 E2 2.5V to 5.5V + GND * CIN1 22uF 10V CIN 10uF 6.3V E5 OFF 3 JP3 C LTC3542EDC 6 RUN 5 MODE/SYNC L1 SW FB 3 VOUT ENABLE 1 ON 2 VIN VOUT 4 1 2.2uH VLF3010AT-2R2M1R0 TDK MODE 1 PULSE 2 BURST 3 JP2 RBM 1.0M JP4 RFB2 1.2V 150K 1% JP5 RFB3 1.5V 100K 1% JP6 D 500mA(max) COUT1 0.1uF RFB1 150K 1% RSD 1.0M VOUT E3 COUT 10uF 6.3V GND D 2 GND VIN GND CFFW 22pF 25V 7 VIN 1 E4 C RFB4 1.8V 75K 1% JP7 RFB5 USER SELECT SYNC (Opt) E1 B GND * B E6 Capacitor CIN1 is an optional part. It was inserted on the DC993A to dampen the (possible) ringing voltage due to the long input leads. On a normal, typical PCB, with short traces, the capacitor is not needed. A 5 4 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. 3 CONTRACT NO. APPROVALS DATE DRAWN Antonina Karpova 10/05/05 CHECKED TITLE LTC3542EDC, Monolithic Synchronous Buck Regulator APPROVED ENGINEER TECHNOLOGY 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 Tom Gross 10/05/05 DESIGNER Friday, September 15, 2006 SIZE CAGE CODE SCALE: 2 FILENAME: DWG NO A REV DC993A 2 SHEET 1 1 OF 1