4 3 2 1 REVISION HISTORY ECO REV - 3 D1 E1 DESCRIPTION APPROVED DATE GEORGE B. 7 - 9- 14 PRODUCTION FAB PV+ DFLS240L E2 4 E11 VIN + VIN C4 10µF 50V 1210 4.4V - 40V 0.4A R3 261k R1 787k PV- or Vin- E3 4.4V - 40V R2 121k RUN R4 ENABLED DISABLED 324k E10 R15 100k 5% U1 LTC4121EUD-4.2 / LTC4121EUD GND E9 3 JP2 16 IN RUN FAULT CHRG 4 15 14 E8 FAULT CHRG INTVCC MPPT INTVCC JP1 INTVcc BOOST ON OFF FREQ R5 3 1.5 MHz 10.0k 750 kHz 7 FREQ sw JP3 6 MPPT BAT E4 12 C3 0.022µF 25V 4 R14 5.1k 5% C5 2.2µF 20% 6.3V 3 R13 47k 5% L1 33.0uH CHGSNS NTC 1 2 8 E5 PROG 13 NTC C2* C1 BATSNS/FB PROG NC/FBG GND R7 3.01k BAT 2.7V - 18V E6 400mA GND M1 Si2343DS * 10 R6 2.0k 5% E7 R12 TO BE CONNECTED TO C2 & C3 9 5 R11 * 11 R12 * J1 OPT DF3-3P-2DSA EPAD 17 1 2 3 2 BAT GND ENTC 2 R10 0 Ohm JUMPER NTC JP4 INT R8 0 Ohm JUMPER EXT * ASSY -A UNLESS NOTED: RESISTORS: OHMS, 0402, 1%, 1/16W CAPACITORS: uF, 0402, 10%, 50V R9 10.0k -B CUSTOMER NOTICE THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS. 4 3 R11 R12 C1 C2 OPEN 0 Ohm 47µF/16V OPEN LTC4121EUD 1.40M 1.05M 22µF/25V 22µF/25V APPROVALS LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS; HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO PCB DES. VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL APP ENG. APPLICATION. COMPONENT SUBSTITUTION AND PRINTED CIRCUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT PERFORMANCE OR RELIABILITY. CONTACT LINEAR TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE. 1 U1 LTC4121EUD - 4.2 2 TECHNOLOGY NC GEORGE B. TITLE: SCHEMATIC 40V 400mA SYNCHRONOUS STEP-DOWN BATTERY CHARGER SIZE N/A SCALE = NONE 1630 McCarthy Blvd. Milpitas, CA 95035 Phone: (408)432-1900 www.linear.com Fax: (408)434-0507 LTC Confidential-For Customer Use Only DATE: IC NO. REV. LTC4121EUD - 4.2 / LTC4121EUD DEMO CIRCUIT 1977A - A / B 7 - 9- 14 SHEET 1 3 1 OF 1 1