19-1863; Rev 0; 11/00 MAX1772 Evaluation Kit Features ♦ Input Current Limiting ♦ ±0.7% Output Voltage Accuracy ♦ Analog Inputs Control Charge Current and Charge Voltage ♦ Monitor Outputs for: Current Drawn from AC Input Source Charging Current AC Adapter Presence ♦ Up to 18.2V Battery Voltage ♦ +8V to +28V Input Voltage Ordering Information PART MAX1772EVKIT TEMP. RANGE 0°C to +70°C IC PACKAGE 28 QSOP ♦ 4A (max) Battery Charge Current ♦ Charges Any Battery Chemistry: Li+, NiCd, NiMH, Lead Acid, etc. ♦ Fully Assembled and Tested ♦ Surface-Mount Components Component List DESIGNATION C1−C4 QTY 4 DESCRIPTION 22µF, 35V low-ESR tantalum capacitors AVX TPSE226M035R0300 or Sprague 593D226X0035E2W DESIGNATION QTY C21, C22, C24 0 Not installed DESCRIPTION D1 1 Schottky diode (DPAK) STM-Microelectronics STPS8L30B or ON Semiconductor MBRD630CT or Toshiba U5FWK2C42 D2 1 30V, 3A Schottky diode Nihon EC31QS03L D3, D4 2 100mA Schottky diodes (SOT23) Central Semiconductor CMPSH-3 or Hitachi HRB0103A C5 1 1µF, 50V ceramic cap (1210) Murata GRM42-2X7R105K050 C6, C7 2 0.47µF, 25V ceramic capacitors (1206) Taiyo Yuden TMK316BJ474ML C8 1 4.7µF, 16V tantalum capacitor Sprague 595D475X0016A2B C9 1 0.022µF ceramic capacitor (0805) L1 1 22µH, 3.6A power inductor Sumida CDRH127-220 C10, C11 2 0.01µF ceramic capacitors (0805) N1 1 N-channel MOSFET Fairchild FDS6680 C12, C13 2 1µF, 10V ceramic caps (0805) Taiyo Yuden LMK212BJ105MG N2 1 N-channel MOSFET Fairchild FDS6612A R1 1 8 0.1µF, 50V ceramic capacitors (0805) Taiyo Yuden UMK212BJ104MG or Murata GRM40-034X7R104M050 0.040Ω ±1%, 1W resistor Dale WSL-2512-R040-F or IRC LR2512-01-R040-F C14−C20, C23 ________________________________________________________________ Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. Evaluates: MAX1772 General Description The MAX1772 evaluation kit (EV kit) is an accurate and efficient multichemistry battery charger. It uses analog inputs to control charge voltage and current. The EV kit can charge any battery with charge current up to 4A. High efficiency is achieved by a buck topology with synchronous rectification. The EV kit provides outputs that can be used to monitor the input current, battery charging current, and the presence of an AC adapter. The MAX1772 EV kit is a fully assembled and tested surface-mount printed circuit (PC) board. Evaluates: MAX1772 MAX1772 Evaluation Kit Component List (continued) DESIGNATION QTY R3, R4 R19−R22 0 DESCRIPTION 0.050Ω ±1%, 1W resistor Dale WSL-2512-R050-F or IRC LR2512-01-R050-F Not installed R2 1 R5 1 8.2kΩ ±5% resistor (0805) R6 1 59kΩ ±1% resistor (0805) R7 1 19.6kΩ ±1% resistor (0805) R8 1 1MΩ ±5% resistor (0805) R9 1 15.4kΩ ±1% resistor (0805) R10 1 12.4kΩ ±1% resistor (0805) R11, R12 2 1Ω ±5% resistors (0805) R13 1 33Ω ±5% resistor (1206) R14, R15 2 4.7Ω ±5% resistors (1206) Selecting the Number of Cells The number of battery-pack cells is selected by jumper JU1 (Table 1). Place the shunt across JU1 pins to select the desired number of cells. This EV kit is shipped configured for 3 cells, 12.6V. Table 1. Jumper JU1 Functions R16 1 220Ω ±5% resistor (0805) R17, R18 2 51kΩ ±5% resistors (0805) SHUNT LOCATION R23, R24 2 50kΩ ±20% potentiometers Mouser 569-68WR-50K or equivalent 1 and 2 Connected to LDO 4 LED1 1 Green light-emitting diode (T-1) 3 and 4 3 JU1 1 6-pin header Connected to R17/R18 divider None 1 Shunt 5 and 6 Connected to GND 2 4 Rubber bumpers 3M SJ-5007 Mouser 517-SJ-5007BK or equivalent None U1 1 MAX1772EEI (28-pin QSOP) U2 1 MAX1615EUK (5-pin SOT23) U3 1 SN74AHC14PWR (14-pin TSSOP) Digi-Key 296-1086-1-ND None 1 MAX1772 PC board None 1 MAX1772 data sheet None 1 MAX1772 EV kit data sheet Detailed Description The MAX1772 EV kit includes all the circuitry needed to charge lithium-ion (Li+), NiMH, and NiCd batteries. The MAX1772 employs a high-efficiency step-down synchronous rectifier that controls both charging voltage and charging current. The control scheme is a constant off-time variable frequency, cycle-by-cycle current mode. 2 The EV kit includes input source-current limiting and analog inputs for setting the charge voltage and charge current. The input current limit on the EV kit has been set to 5.1A. The voltage at ICTL, set by potentiometer R24 (50kΩ) along with resistor R2 (0.050Ω), sets the charging current (4A). The voltage at VCTL, set by potentiometer R23 (50kΩ), adjusts the battery output voltage range. The VCTL range is from 0 to REFIN (3.3V). Refer to the MAX1772 data sheet for more detailed information. CELL PIN NUMBER OF CELLS AC Adapter Detection The AC adapter input voltage is connected through a voltage-divider (R6/R7) to ACIN of the MAX1772 to detect when AC power is available for charging. LED1 turns on whenever the AC adapter input voltage falls below 8V. Current Measurement The board’s ICHG pad is used to monitor the batterycharging current. The ICHG voltage range is 0 to 3V. VICHG is proportional to the charge current by: VICHG = 0.77 ✕ ICHG (V) The board’s IINP pad is used to monitor the system input current. The IINP voltage range is 0 to 3V. VIINP is proportional to the AC adapter current by: VIINP = 0.496 ✕ IADAPTER (V) Refer to the Current Measurement section of the MAX1772 data sheet for information on V ICHG and VIINP. _______________________________________________________________________________________ _______________________________________________________________________________________ U3–B LE01 R16 220Ω 4 3 2 C17 0.1µF IINP ICHG 7 14 1 R23 50k ±20% U3–A JU2 3.3V 3 1 3.3V R20 OPEN R18 51k 2 R19 OPEN R7 19.6k 1% R6 59k 1% 3 R17 51k C11 0.01µF C10 0.01µF C13 8.2µF 10V D4 CMPSH-3 JU3 2 R10 12.4k 1% R9 15.4k 1% 1 JU1 2 4 3 6 5 LD0 1 3 3 2 1 (CUT HERE) 2 R24 50k ±20% TP1 C9 0.022µF C5 0.022µF 50V 1 NOTE: ALL RESISTORS ARE 5% UNLESS OTHERWISE NOTED. GND R22 OPEN TP2 R21 OPEN R8 1M R5 8.2k R4 OPEN R3 SHORT C20 0.1µF C14 0.1µF CLS 28 10 16 14 15 13 12 11 5 6 7 IINP ICHG CELL ICTL VCTL REFIN ACOK ACIN CCS CCI CCV 8 GND 9 GND 3 1 DCIN 4 REF MAX1772 U1 22 25 BATT CSIN CSIP PGND DLO LX 17 18 19 20 21 23 DHI 24 DLOV BST C19 0.1µF JU1 1-2 3-4 5-6 1µF 10V C18 0.1µF C6 0.47µF 25V C7 0.47µF 26 25V LDO 2 CSSN CSSP 27 5 6 1 1 CELLS 4 3 2 N2 4 N1 4 5 6 R15 4.7Ω C21 OPEN R11 1Ω 3 2 3 2 8 7 8 7 R1 0.04Ω 1% 1W D1 C4 22µF 35V 3.3V LOAD R2 0.050Ω 1% 1W L1 22µH C23 0.1µF D3 CMPSH-3 3 C1 22µF 35V C22 OPEN R12 1Ω R14 4.7Ω C4 22µF 35V C15 0.1µF C3 22µF 35V C2 22µF 35V 1 2 LOAD 3 2 1 EXTLOAD OUT GND IN BATT GND C16 0.1µF R13 33Ω MAX1615 U1 C21 OPEN 11 9 5 13 5/3 (FB) SHDN LDO U3–E 4 5 U3–D U3–C U3–F 10 8 6 12 Evaluates: MAX1772 ADAPTER_IN JU1 MAX1772 Evaluation Kit Figure 1. MAX1772 EV Kit Schematic 3 Evaluates: MAX1772 MAX1772 Evaluation Kit 1.0" 1.0" Figure 2. MAX1772 EV Kit Component Placement Guide— Component Side 1.0" Figure 3. MAX1772 EV Kit PC Board Layout—Component Side 1.0" Figure 4. MAX1772 EV Kit PC Board Layout—Solder Side Figure 5. MAX1772 EV Kit Component Placement Guide— Solder Side Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 4 _____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2000 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.