The Texas Instruments BQ25170 Linear Battery Charger is an integrated 800mA linear charger for single-cell lithium-ion, lithium polymer, and LiFePO4 batteries, targeted for portable applications with limited space. The device has a power output that charges the battery. The system load can be placed parallel to the battery, as long as the average system load does not prevent the battery from fully charging within the safe timer duration. When the system load is in parallel with the battery, the charging current is shared between the system and the battery.

     Texas Instruments' BQ25170 has three stages of charging a lithium-ion battery: pre-charging to restore a fully discharged battery, rapid charging at constant current to provide a large amount of charge, and regulating the voltage to reach full capacity. During all charging phases, the internal control loop monitors the IC junction temperature and lowers the charging current if the internal temperature threshold, TREG, is exceeded.

     The charger power level and charge current detection function are fully integrated. Charger function with high precision current, voltage regulation loop, charging state display, automatic charging termination. The charging voltage and fast charging current can be programmed using external resistors. Pre-charge and termination charge current thresholds track fast charge current Settings.