5 4 3 2 1 REVISION HISTORY E8 R27 INTVCC R9 0 2 E4 ECO REV DESCRIPTION DATE APPROVED 2 PROTO 07/27/11 JIAN L. INTVCC MODE/PLLIN P.S. BURST CCM 1 4 JP1 100k 1% 3 PGOOD MODE/PLLIN RUN E1 ON 1 JP2 RUN OFF 3 VIN D R1 OPT R10 100k 2 D C23 OPT EXTVCC R2 OPT E5 VOUT GND E12 CLKOUT INTVCC 15 R36 0 R5 OPT C27 220nF R3 220nF R4 OPT OPT 4 5 Q1 BSC050NE2LS CIN4 10uF 25V 1210 Q2 OPT 4 CIN1 180uF 16V J2 4.5V ~ 14V GND E6 VOUT L1 0.33uH C25 0.1uF 10V J3 SW 12 INTVCC Q3 BSC010NE2LS 4 C VOUT 744301033 COUT6 COUT3 100uF 100uF 6.3V 6.3V 1210 1210 DCR=0.32mOHM 5 13 + GND CMDSH-3 14 CIN3 10uF 25V 1210 CIN2 180uF 16V D2 1 2 3 16 Q4 OPT 4 + COUT1 330uF 2.5V 7343 + COUT2 1.5V / 30A 330uF 2.5V 7343 J4 GND ILIM C22 C31 4.7uF 10V 0805 17 R42 3.01k 1% 1 2 3 CLKOUT EXTVCC E11 INTVCC 18 1 2 3 EXTVCC E10 C21 1uF BG + 11 CLKOUT SW VIN 5 19 ITEMP 20 PGOOD 21 22 FREQ MODE/PLLIN 23 SNSD+ 25 C29 OPT TG DIFFP OPT R38 20k 1% BOOST ILIM VOUT VIN DIFFN 10 6 EXTVCC DIFFOUT 9 5 LTC3866EUF INTVCC SNSA+ 4 R41 OPT VFB 8 C R39 30.1k 1% C32 3 7 R40 10k 1% 2 R34 0 C28 220pF ITH SNS- 1 RUN 24 TK/SS R35 OPT SGND C24 0.1uF 10V VIN VIN R37 2.2 1 2 3 U1 TRK/SS C26 1.5nF J1 C19 1uF 5 R32 0 PGND E2 VIN VIN ITEMP R30 931 1% R28 1k 1% R43 R44 4.64k 0 1% C33 OPT R31 10 R45 10 CLKOUT R6 OPT B E14 B VO_SNS+ VO_SNSE13 VOUT C16 100uF 6.3V 1210 J5 VOUT 2 C34 R48 OPT OPT + COUT4 330uF OPT 7343 + COUT5 330uF OPT 7343 IOUT 1 C15 100uF 6.3V 1210 D 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. G R12 0.010 2512 R18 OPT 2512 4 3 E15 R11 10K IOSTEP CLK E7 GND CONTRACT NO. APPROVALS PCB DES. TECHNOLOGY MI ENG. JIAN L. 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 Fax: (408)434-0507 LTC Confidential-For Customer Use Only TITLE: SCHEMATIC HIGH EFFICIENCY STEP-DOWN CONVERTER WITH VERY LOW DCR INDUCTOR THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 5 VOUT S CUSTOMER NOTICE A Q5 SUD50N03-09P 1 1 RN1 OPT J6 2 3 4 5 R47 OPT LOAD STEP CIRCUIT 5 4 3 2 TEMPERATURE COMPENSATION NETWORK FOR DCR SENSING ITEMP SIZE IC NO. N/A PCB NO. DATE: 2 REV LTC3866EUF DEMO CIRCUIT 1829A Wednesday, December 21, 2011 SHEET 1 2 1 OF 1 A