A B C D E REVISION HISTORY ECO REV DESCRIPTION 0 1st PROTOTYPE DATE APPROVED <DATE> <APPROVED> 4 4 & R4 ARE OPTIONAL COMPONENTS. THEY ARE INSERTED * CIN1 ON THE DC1429A TO DAMPEN THE (POSSIBLE) RINGING VOLTAGE DUE TO THE LONG INPUT LEADS. ON A NORMAL, TYPICAL PCB, WITH SHORT TRACES, THIS COMPONENTS ARE NOT NEEDED. U1 LTC3642EDD E1 2 VIN 4.5V - 45V CIN 2.2uF 50V 1210 R4 4.7 Ohm * 5 7 3 CIN1 0.22uF 100V * E2 4 GND VIN RUN VFB HYST ISET SS CSS 6800pF R1 2M SW GND GND 1 L1 100uH VLCF5020T-101MR27 E3 COUT 10uF 6.3V 1206 TDK 6 VOUT 50mA(max) COUT1 0.1uF 16V E4 GND 3 3 8 CFFW RSET (Opt) E5 9 (Opt) SGND RFB1 1.47M 1% E6 SGND RUN 1 ON R2 2 2 (Opt) 3 OFF RFB4 280K 1% RFB3 475K 1% RFB2 1.18M 1% JP4 5V JP3 3.3V JP2 1.8V R3 0 Ohm JP1 2 APPROVALS 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. 1 A B DRAWN: Rudy Bautista ENGINEER: APPROVED: CHECKED: Date: C Tom Gross LINEAR TECHNOLOGY CORPORATION 1630 McCARTHY BLVD MILPITAS, CA. 95035 (408)432-1900 (408)434-0507 (FAX) Title: LTC3642EDD www.linear.com LTC Confidential For Customer Use Only High Efficiency 50mA Monolithic Synchronous Buck Regulator SD Document Number Thursday, September 11, 2008 C:\ORCADWIN\CAPTURE\1429A\1429A_REV1.DSN D Rev Demo Circuit 1429A Sheet E 1 1 of 1 1