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 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 Applications Engineering for assistance. ECO REV DESCRIPTION 1 D DATE PROTO D Q2 Si9803DY OPT [1] VIN 1 2 3 JP1 4 C6 10uF 10V C13 10uF 10V 6 0.1uF 10V JP3 U1 LTC3809EDD-1 C TG C12 1 OPT [1] OPT [1] OPT 4 L1 [1] 8 2 4 R5 Q3 Si9804DY 3 VIN FORCED CONTINUOUS SW C10 10 C SD14-1R5 L2 MODE SW VOUT IHLP-2525CZ-01-1.5 OPT OPT [1] [1] RUN C5 22uF 6.3V C9 10uF 6.3V TP6 VOUT 1.8V@2A C2 + 150uF 4V TP10 OPT TP4 5 GND 5 6 7 8 PULSE-SKIPPING TP2 1 2 3 JP2 9 R11 100K VFB [1] VIN 2.75V-9.8V C7 10uF 10V OPT TP1 5 6 7 8 Q1 FDC6020C 1 5 BURST C1 APPROVED 12/08/04 [1] GND RUN BG 7 VIN TRACK TP5 R9 R8 1.18K 1% JP4 1 R12 10K 590 1% TRACK VIN SOFT START R3 1 2 3 2 TRACK/SS IPRG VFB 2 VFB 3 ITH 4 OPT C4 470pF [1] 11 0 IPRG 6 C8 GND B C11 R2 100pF 15K R4 59K 1% UNLESS OTHERWISE SPECIFIED DIMENSIONS ARE IN INCHES TOLERANCE ON ANGLE - - 2 PLACES - - - 3 PLACES - - INTERPRET DIM AND TOL PER ASME Y14.5M -1994 A THIRD ANGLE PROJECTION NOTES: UNLESS OTHERWISE SPECIFIED, [1] C3 150pF CONTRACT NO. APPROVALS DRAWN MEI DATE 12/08/04 CHECKED TECHNOLOGY TITLE DESIGNER SIZE CAGE CODE DWG NO REV 1 DC882A DO NOT SCALE DRAWING 4 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 SCH, LTC3809EDD-1, SYNCHRONOUS STEP-DOWN CONVERTER WITH OUTPUT TRACKING ENGINEER 2. WHEN USING LTC3809EDD WITH SPREAD SPECTRUM MODE, SELECT "SOFT START", R3=300K; JP1, JP2 AND JP3 ARE OPEN; C12=2200pF, R5=0, C10=1000pF. 3 B TP9 APPROVED DO NOT STUFF (OPTIONAL). 5 R6 118K 1% Wednesday, May 18, 2005 SCALE: NONE 2 FILENAME: 882A-1.DSN SHEET 1 1 OF 1 A