5 4 3 2 1 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 DATE 2 PROD 04/21/11 CHARLIE Z. 05/11/11 Charlie Z. 1 VIN Q1 2 SUD50N03-09P-E3 D E1 VIN+ Schematic corrections 2.1 CIN2 [1] [1] CIN3 [1] J2 CIN5 CIN6 CIN7 OPT OPT OPT OPT VININTVCC D1 R24 CBst 0.22uF SW 8 1M [1] RUN/SS R23 1 12 NC 21 NC 24 NC 25 NC 28 INTVCC 32 INTVCC 31 LTC3608 BOOST 0.1uF 16 PGOOD 17 VRNG INTVCC R26 [1] R2 100pF 18 10K RTH 1500pF 12K 34,35,36, 37,38,39, E4 R30 162K 1% B INTVCC EXTVCC 29 VFB 23 VISAHY IHLP2525CZ-01 VOUT OPT COUT3 OPT VO+ E7 COUT6 22uF 6.3V COUT5 22uF 6.3V COUT2 100uF 6.3V COUT1 100uF 6.3V VOUT [1] J4 J3 C C7 4.7uF 10V GND E8 1 VO- SVIN C9 0.47uF 50V E9 C10 OPT EXTVCC C11 VOUT OPT R29 JP2 10 R16 40.2K 1% 1.5V JP3 SVIN JP4 1 19.1K 1% 2.5V 2 3 JP8 B R19 30.1K 1% R20 1.8V CCM COUT4 VIN INTVCC R28 FCB DCM DYNAMIC LOAD CIRCUIT L1 [1] 60.4K 1% 19 Cth ITH 30 J5 IOSTEP 10mV/A 0.010 1% 27 Cthp SVIN 10,14,15, 20,26,54, E3 VON SGND C8 0.1uF PGND 13 R1 10K R25 VOUT CSS R27 RUN/SS ION 3 JP7 100K 9 [1] 2 OFF RPG 11 22 ON INTVCC NC SW FCB C SW 33,41,42,43, 44,45,46,55, SW 47 1,2,3,4,5,6,7,48, 49,50,51,53, 52 PVIN PVIN SGND 3 U1 [1] E2 PGOOD IOSTEP_CLK OPT R31 OPT 40 GND CIN4 D E10 C12 CIN1 + [1] J6 VOUT C2 1uF 10V 1 J1 VIN C13 1uF 10V APPROVED JP5 R21 3.3V 13.7K 1% C6 VOUT SELECT (Opt) [1] A ASSY VIN -A 5V - 20V VOUT 8A MAX D1 CMDHS-3 CIN1 150uF, 35V CIN2, CIN3 U1 R26 R23 10uF, 35V LTC3608EWKG OPT 3.3 W L1 1.0uH CONTRACT NO. APPROVALS DRAWN MI -B 9V - 32V 6A MAX SDM10K45 100uF, 50V 10uF, 50V LTC3609EWKGHV 35.7K 4.7 W 1.5uH DATE 08/21/07 CHECKED TECHNOLOGY TITLE 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 A SCH, LTC3608EWKG/LTC3609EWKGHV, 8A HIGH POWER DENSITY STEP-DOWN CONVERTER APPROVED ENGINEER SIZE CAGE CODE DESIGNER DWG NO REV 2.1 DC1320A Friday, May 11, 2012 5 4 3 2 SCALE: FILENAME: 1320A-2.1.DSN SHEET 1 1 OF 1