5 4 3 2 1 * Capacitor C5 is an optional part. It was inserted on the DC734 to dampen the (possible) ringing voltage due to the use of long input leads. On a normal, typical PCB, with short traces, the capacitor is not needed. Vin Vin 2.5V-5.5V JP1 CH.1 On 2 Off Gnd On 2 R1 4.7M 5% U1 LTC3407-2EDD R2 100K R3 4.7M 5% Off VIN 1 E5 JP2 CH.2 1 Cin 10uF 6.3V 3 D C5* + 47uF 10V (Opt.) 3 E1 3 D Vout1 1.2V/1.5V/1.8V @ 800mA R4 604K RUN2 9 R5 604K R8 402K SW2 1 FBK1 11 GND R9 301K 5 2 4 6 + + + Vin 1 3 5 7 C2 22pF FBK2 C Vout2 2.5V @ 800mA R6 887K Cout2 10uF 6.3V C4 (Opt.) 10 E3 Gnd R7 280K E6 R10 4.7M 5% B 2 JP3 Vout1 E7 L2 2.2uH C1 22pF + + + B POR MODE/SYNC Cout1 10uF 6.3V 1.2V 1.5V 1.8V E4 SW1 L1 2.2uH C3 (Opt.) Gnd 4 POR 8 6 E2 RUN1 GND C 2 3 JP4 1 Burst Pulse Mode Skip LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY Customer Notice A 5 4 LINEAR TECHNOLOGY CORPORATION 1630 McCARTHY BLVD. MILPITAS, CA. 95035 408-432-1900 408-434-0507 FAX 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. Size Document Number This Circuit Is Proprietary To Linear Technology And Supplied For Use With Linear Technology Parts. Date: Wednesday, June 23, 2004 3 Title A Dual Synchronous Step-Down DC/DC Converter Rev Demo Circuit 734A LTC3407-2EDD 2 Sheet 1 1 of 1