5 4 RPG 100K FC (FORCED CONTINUOUS) BM (BURST MODE) SYNC PS (PULSE-SKIP) EXT SS INT SS TRACK 2 17 Track/SS SW 16 Ith Vfb 8 D1 Opt. E8 RSET 105K JP1 2.5V RTR1 255K RFB5 845K 1% JP3 5V RFB2 187K 1% C COUT1 0.1uF GND GND E5 JP4 Opt. RFB3 115K 1% B RFB4 Opt. RTR2 200K Customer Notice * Capacitor CIN1 Is An Optional Capacitor. It Is Inserted On The DC1442A To Dampen The (Possible) Ringing Voltage Due To The Long Input Leads. On A Normal, Typical PCB, With Short Trace, The Capacitor Is Not Needed. 5 CFFW 10pF JP2 3.3V RFB1 267K 1% LTC CONFIDENTIAL - FOR CUSTOMER USE ONLY A COUT 100uF 6.3V E4 B TRACK VOUT 2.5A Max E3 2 SW 2 18 RUN L1 3.3uH Vishay IHLP-2525CZ-01 1 2 4 6 SW Sync/Mode CBST 0.22uF 1 1 3 5 SW 19 RC 4.32K CC 1000pF JP7 TRACK 20 1 CC1 Opt. Boost DBST CMDSH-3 2 7 3 1 11 INTVcc CST 1uF 2 PVin 10 RSD 4.7M CSS 0.1uF 2 4 JP5 VOUT ENABLE 1 ON 2 OFF 3 C PVin PGnd PGnd PGnd PGnd SGnd PGnd E2 1 PGood 5 U1 LTC3603EUF 12 13 14 15 9 21 CIN 22uF 25V CIN2 0.1uF 16V Opt. Rt GND * CIN1 3.3uF 35V 6 E1 PGOOD E7 E6 VIN 4V - 15V D 1 JP6 MODE/SYNC 1 2 3 4 5 6 7 8 1 SYNC 1 RBM1 845K CBM 0.1uF 10V Opt. D 2 2 RBM2 137K 3 4 LINEAR TECHNOLOGY CORPORATION 1630 McCARTHY BLVD. MILPITAS, CA. 95035 408-432-1900 408-434-0507 FAX 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. Size Document Number This Circuit Is Proprietary To Linear Technology And Supplied For Use With Linear Technology Parts. Date: Wednesday, February 04, 2009 3 www.linear.com A LTC3603EUF Title High Input Voltage 2.5A Monolithic Synchronous Buck Regulator 2 Rev A Demo Circuit 1442A Sheet 1 1 of 1