A B C TP3 TP2 3 15 20 2 1 1 TRACK J3 TRACK/SS RSS1 4.87M 1% RTR1 TP7 100k 1% RTR2 opt. 1% INT SS 1 2 TRACK 3 4 EXT SS 5 CSS1 0.01uF 16 Track/SS DDR Mode RSD1 4.87M 1% J2 2 SW SW SW SW 5 6 11 12 Ith 19 Run 17 RUN ON OFF NC NC NC 4 7 10 Vfb 18 1 2 6 R2 Rt 3 4 EXT SYNC 5 6 RT2 opt. 1% J6 Rt / SYNC RM1 4.87M 1% 2 (FORCED CONTINUOUS MODE) FCM RT1 165K 1% J1 MODE 1 2 (PULSE-SKIP MODE) PSM 3 4 (BURST MODE EXTERNAL CLAMP) (BURST MODE) BMEC 5 6 BM 7 8 C1 10pF COUT4 100uF 6.3V opt. TP4 COUT5 + COUT6 10uF 100uF 6.3V opt. TP5 1.2V GND JP2 2 ON 3 4 OFF 52.3K 1% RM5 opt. 1% R5 JP4 36.5k 1% R6 JP5 R4 R1 165k 1% 1.8V Voutset JP3 2.5V RM3 301k 1% 3.3V TP6 TP9 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. C 2 RM4 100k 1% CONTRACT NO. APPROVALS DRAWN Antonina K. DATE 7/13/09 CHECKED APPROVED ENGINEER GND 3 VBMCV (Vout Burst Mode Clamp Voltage) CUSTOMER NOTICE GND USER SELECT SET EXT B COUT3 100uF 6.3V opt. CITH1 1000pF JP1 J9 1 TP10 (Burst Mode External Clamp Voltage) COUT2 33uF 6.3V CFF1 22pF 1 opt. BMECV A COUT1 33uF 6.3V RITH1 15k 1% 82.5K 1% RM2 4.87M 1% SYNC TP8 CC1 opt. 165K 1% J4 DDR 4 VOUT 3A 3 R3 INT SYNC L1 0.47uH VISHAY IHLP2020BZERR47M01 2 RFILT1 24 PVin PVin PVin_d SVin SGND 8 9 13 14 CFILT1 1uF EXT 1 3 CIN1 22uF 6.3V PGood CIN2 22uF 6.3V PGND GND CIN4 100uF opt. INT LTC3612EUDC 21 CIN3 + 100uF 10V Rt/Sync VIN U1 2 TP1 2.25V - 5.5V 3 RPG1 100k 5% 4 1 E J5 COMP PGOOD 3 D T. Gross 7/13/09 DESIGNER Tuesday, July 21, 2009 TECHNOLOGY TITLE 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC3612EUDC 3A Monolithic Synchronous Step-Down Regulator SIZE CAGE CODE FILENAME: SCALE: D DWG NO REV 2 DC1310A SHEET 1 E 1 OF 1