DESCRIPTION
The LTC®1731 is a complete constant-current/constant voltage linear charger controller for single cell lithium-ion batteries. Nickel-cadmium (NiCd) and nickel-metal-hy dride (NiMH) batteries can also be charged with constant current using external termination. The external sense resistor sets the charge current with 5% accuracy. An internal resistor divider and precision reference set the final float potential with ±1% accuracy. The output float voltage is set internally to 4.1V (LTC1731-4.1) or 4.2V (LTC1731-4.2).

FEATURES
■ Complete Linear Charger Controller for 1-Cell Lithium-Ion Batteries
■ 1% Voltage Accuracy
■ Programmable Charge Current
■ C/10 Charge Current Detection Output
■ Programmable Charge Termination Timer
■ Space Saving 8-Pin MSOP Package
■ Automatic Sleep Mode When Input Supply is Removed (7µA Battery Drain)
■ Automatic Trickle Charging of Low Voltage Cells
■ Programmable for Constant-Current-Only Mode

APPLICATIONS
■ Cellular Phones
■ Handheld Computers
■ Charging Docks and Cradles
■ Programmable Current Source