5 4 3 2 1 * Capacitor C5 is an optional part. It was inserted on the DC701 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 2.5V-5.5V JP1 CH.1 On 2 Off Gnd On 2 R1 4.7M 5% U1 LTC3407EDD R2 100K R3 4.7M 5% Off VIN 1 E5 JP2 CH.2 3 Cin 10uF 6.3V 1 C5* + 47uF 10V (Opt.) D 3 E1 Vin 3 D R4 604K RUN2 9 R5 604K R8 402K SW2 1 FBK1 11 GND R9 301K C Vout2 2.5V @ 600mA 5 2 4 6 C2 10pF FBK2 R6 887K Cout2 10uF 6.3V C4 (Opt.) 10 E3 Gnd R7 280K E6 B 2 Vin 7 R10 4.7M 5% 1 3 5 + + + JP3 Voltage Select E7 L2 2.2uH C1 10pF + + + 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 Vout1 1.2V/1.5V/1.8V @ 600mA 2 3 JP4 1 Burst Pulse Mode Skip LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY 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. A 5 4 3 LINEAR TECHNOLOGY CORPORATION 1630 McCARTHY BLVD. MILPITAS, CA. 95035 408-432-1900 408-434-0507 FAX A Title Dual Synchronous Step-Down DC/DC Converter Size Document Number Date: Monday, November 10, 2003 Demo Circuit 701A 2 LTC3407EDD Sheet 1 1 of 1 Rev