5 4 3 2 1 REVISION HISTORY ECO REV DESCRIPTION DATE APPROVED - 4 PRODUCTION 04/07/10 JESUS R. SENSE E3 R27 0.1 R28 0.1 R29 0.1 R30 0.1 4527 4527 4527 4527 E6 VOUT 5V , 3A C7 D Vsns E1 C14 4.7uF 0.020 1% 50V 10V 7343 25V 50CE22BS OPTION D E5 GND R7 68.1k R6 10k 0 LOW HIGH 1 23 18 INTVCC DIV0 22 DIV2 VPP ROSC 15 OSC TP1 OSC U2 LT4180EGN R23 22.1k 47pF R34 1k 0SC 19 14 3 C30 R26 1% 1% D2 CMDSH-3 COSC DRAIN 1% 13 R21 5.36K OV CHOLD4 2 INTVCC SYNC 24 21 20 R9 30.1k C SPREAD 1% 11 1% 1 GUARD4 INTVCC 2 HIGH 10 10V 3 9 10V R20 2.15k JP5 LOW 1 CHOLD3 47uF 1 1uF SPREAD 2 8 C16 47uF SENSE C15 R22 100k 3 17 HIGH VC D1 MBRA340T3G GUARD2 SYNC 9 FB CHOLD1 RT 11 L1 6.8uH VIN 0.47uF 3 2 1 5 6 3 4 10 SW 1% C10 PG FB R19 1.87k 2 GND 8 RUN/SD BOOST 12 7 C 1uF RUN 5 50V 2 BD C21 0.1uF 1 1 4 VIN 2 1% Vsns JP4 3 GUARD3 U1 LT3693EDD DIV0 CHOLD2 100k C22 COMP JP1 3 DIV1 JP3 DIV1 R15 21.5k RUN DIV2 JP2 LOW R14 OFF 10V 7343 + C23 R18 100k Vsns LOW Vsns R17 100k HIGH Vsns R16 100k 7 C13 22uF 50V + E2 ON C31 470uF INTVCC 16 8V - 36V GND + 470uF R25 6 VIN C8 + 470uF C24 2.2nF R24 1% C28 C26 C25 C27 4.7nF 470pF 470pF 10nF C29 330pF 33.2k 1% DRAIN B OPTIONAL CIRCUIT C32 5 OPT OPT SYNC 4 2Y 1A 2A 1 OSC DRAIN 2 3 3 Q1 INTVCC 1 R32 R35 OPT SN74LVC2G14DBVT OPT NOTES: UNLESS OTHERWISE SPECIFIED, C35 OPT 1. RESISTOR AND CAPCITOR CASE SIZE IS 1206. 2. INSTALL SHUNTS IN LOCATIONS INDICATE. C36 OPT TP2 CASCODE R33 OPT 2N7002 OPT OPTIONAL CIRCUIT 2 D3 1Y C34 OPT U3 GND VCC 6 B COMP INTVCC OPT COMP CUSTOMER NOTICE C33 OPT 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. A APPROVALS PCB DES. APP ENG. TECHNOLOGY MI JESUS R. TITLE: SCHEMATIC 3A STEP-DOWN REGULATOR WITH VIRTUAL REMOTE SENSE SIZE N/A THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 4 3 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only SCALE = NONE 2 IC NO. LT4180EGN REV. DEMO CIRCUIT 1504A DATE: Monday, July 26, 2010 SHEET 1 1 4 OF 1 A