5 4 3 2 1 REVISION HISTORY INTVCC E10 ECO REV CVCC1 DESCRIPTION 1 CTR1 4700pF TRACK/SS1 1uF CVCC E9 INTVCC 1uF 3 SS 2 3 JP3 RTR1 0 TOM G. 1 2 TRACK APPROVED 05/16/11 TRACK/SS2 1 SS D DATE PRODUCTION CTR2 4700pF TRACK D JP4 E11 RTR2 0 TRACK2 TRACK1 RTR3 OPT RTR4 OPT VIN VIN RPG1 100K RPG2 100K E1 E8 PGOOD2 PGOOD1 INTVCC PHASE RUN1 1 VIN 2 D1 20 INTVCC VISHAY IHLP-2020BZER1R0M01 COUT1 22uF 6.3V 1206 5 1.8V CC1 10pF OPT R7 19.6K 1% ITH1 ITH1 RITH1 13K 1% EXT D2 FB2 ITH2 2.2uH VISHAY IHLP-2020BZER2R2M01 COUT2 22uF 6.3V 1206 12 CFFW2 9 R4 84.5K 1% 10pF VOUT2 COUT4 22uF 6.3V 1206 COUT6 10uF 6.3V 0805 3A E7 GND E14 11 R10 26.7K 1% RITH2 13K 1% GND JP15 2.5V CC2 10pF OPT ITH2 R6 18.7K 1% JP5 1 EXT CITH1 CITH2 2 220pF 220pF 3 3.3V INT R8 11.5K 1% JP7 5V INTVCC MODE 1MHz 2MHz (INT.) B JP13 INTVCC 1 CIN1 47uF 16V 1210 E5 VOUT2 0.1uF FREQ CIN3 47uF 16V OPT 1210 CLDO 1uF OPT OPT INTVCC JP12 VIN1 [1] + CIN5 22uF 35V 7343 C2P5 1uF INTVCC CBST2 3 INT 3.6V - 15V V2P5 17 14 13 C E13 18 2 R9 14.7K 1% E2 JP2 6 LTC3633EUFD JP6 VIN GND OFF U1 1 B 8 15 16 PVIN2 PVIN2 19 10 27 FB1 MODE/SYNC 6 3 4 1.5V VON2 RT 1.2V 3 VON1 5 1 4 SW2 SW2 PGND 28 10pF VOLTAGE SELECT 2 ON 2 CFFW1 26 GND SW1 SW1 29 E15 23 24 25 R3 29.4K 1% R5 29.4K 1% GND 1M L2 0.1uF COUT3 22uF 6.3V 1206 BOOST2 GND E6 COUT5 10uF 6.3V 0805 V2P5 BOOST1 R2 L1 1.0uH OPT VOUT1 3A RUN2 PHMODE 7 E4 CBST1 RUN1 PGOOD2 3 TRACK/SS2 JP1 INTVcc JP11 C TRACK/SS1 3 OFF PGOOD1 1M 1 2 3 E3 1 R1 1M 21 22 ON PVIN1 PVIN1 RPHMDE 2 VOUT1 RUN2 1 ON OFF VIN 2 2 1 BURST MODE 3 4 3 SYNC 6 5 FCM (FORCED CONTINUOUS MODE) INTVCC JP14 VIN RT 324K 1% E16 E12 SYNC R11 10k JP8 VIN2 3.6V - 15V [1] + CIN6 22uF 35V 7343 CIN4 47uF 16V OPT 1210 CIN2 47uF 16V 1210 CUSTOMER NOTICE NOTES: UNLESS OTHERWISE SPECIFIED, A [1] CIN5 AND CIN6 ARE INSERTED ON DC1347 TO DAMPEN THE (POSSIBLE) RINGING VOLTAGE DUE TO THE USE OF LONG INPUT LEADS. ON A NORMAL, TYPICAL PCB, WITH SHORT TRACES, CIN5 AND CIN6 ARE NOT NEEDED. 2. ALL RESISTOR AND CAPACITOR CASE SIZE ARE 0402. 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. 5 4 3 APPROVALS TECHNOLOGY PCB DES. MI APP ENG. TOM G. TITLE: SCHEMATIC SIZE N/A SCALE = NONE 2 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only DATE: DUAL SYNCHRONOUS STEP-DOWN REGULATOR IC NO. LTC3633EUFD DEMO CIRCUIT 1347B Monday, May 16, 2011 SHEET 1 1 REV. 1 OF 1 A