LTC1731-8.4 Datasheet | Linear Technology

LTC1731-8.2/LTC1731-8.4 Lithium-Ion Linear Battery Charger Controller Features s s s s s s s DESCRIPTIO s s plete Linear Charger Controller for 2-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 (15µA Battery Drain) Automatic Trickle Charging of Low Voltage Cells Programmable for Constant-Current-Only Mode The LTC ®1731-8.2/LTC1731-8.4 are plete constantcurrent/constant-voltage linear charger controllers for 2cell lithium-ion (Li-Ion)batteries. Nickel-cadmium (Ni Cd) and nickel-metal-hydride (Ni MH) batteries can also be charged with constant current using external termination. The external sense resistor sets the charge current with 7% accuracy. An internal resistor divider and precision reference set the final float potential with 1% accuracy. The output float voltages are set internally to 8.2V (LTC1731-8.2) or 8.4V (LTC1731-8.4). When the input supply is removed, the LTC1731-8.2/ LTC1731-8.4 automatically enter a low current sleep mode, dropping the battery drain current to typically 15µA. An internal parator detects the end-of-charge (C/10) condition while a programmable timer, using an external capacitor, sets the total charge time. Fully discharged cells are automatically trickle charged at 10% of the programmed current until battery voltage exceeds 4.95V. The LTC1731-8.2/LTC1731-8.4 are available in the 8-pin MSOP and SO packages. For 1-cell Li-Ion battery charging, see the LTC1731-4.1 and LTC1731-4.2 data sheets. U APPLICATIO S s s s s Cellular Phones Handheld puters Charging Docks and Cradles Programmable Current Source , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATIO 400m A Li-Ion Charger VIN = 9V MBRM120T3 Typical Li-Ion Charge Cycle CONSTANT CURRENT CONSTANT VOLTAGE BATTERY VOLTAGE 400 300 CHARGE CURRENT 200...