A B C D E REVISION HISTORY This circuit is proprietary to Linear Technology and supplied for use with Linear Technology parts. Customer Notice: Linear Technology has made a best effort to design a circuit that meets customer-supplied specifications; however, it remains the customers 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 Applications Engineering for assistance. ECO REV DESCRIPTION 0 1st PROTOTYPE 1 2.5A to 3A DATE APPROVED 12/04/03 <APPROVED> 09/21/05 4 4 TP1 CIN3 + 100uF 10V 2.25V-5.5Vin TP2 GND CFF 22pF JP1 R2 RPG 100K 3 U1 LTC3412AEFE TP3 PGOOD C1 1 CITH 100pF 1000pF J1 RITH 7.50K 1% R3 R1 ROSC 75.0K 1% 110K 1% 309K 1% BURST MODE FORCE CONTINUOUS 3 4 5 CSS 1000pF CIN2 2.5V 16 PGOOD SW 15 ITH SW 14 VFB PGND 13 RT PGND 12 R6 (Opt) SYNC/MODE SW 11 7 RUN/SS SW 10 SGND PVIN 392K 1% JP3 R5 L1 1uH TOKO A921CY-1R0M CIN1 22uF 6.3V 3.3V 576K 1% D1 (Optional) 9 3 JP2 R4 22uF 6.3V PVIN SVIN 6 8 RSS 1.0M J2 2 2 1.8V 232K 1% JP4 USER SELECT TP4 COUT1 100uF 6.3V TDK COUT2 10uF 6.3V + COUT3 100uF (Optional) Vout 3A TP5 GND ON 2 OFF TP6 GND PCB Layout U1 R1 CIN2 RPG R3 1 C1 CITH RITH 1630 McCARTHY BLVD MILPITAS, CA. 95035 (408)432-1900 (408)434-0507 (FAX) ROSC DRAWN: Rudy Bautista L1 ENGINEER: Tom Gross COUT1 RSS CIN1 CSS B Title APPROVED: Size CHECKED: DCxxxA_00.PCB A LINEAR TECHNOLOGY CORPORATION APPROVALS C xxxA_x.DSN Date: D www.linear.com 1 LTC Confidential For Customer Use Only 3A Monolithic, Synchronous Step-Down Regulator Document Number Tuesday, May 05, 2009 Rev Demo Circuit 652A Sheet 1 E 1 of 1