800-mA linear charger for one-cell Li-ion and LiFePO4 with VINDPM and JEITA

The BQ25176K is an

integrated 800mA linear charger for 1-cell Li-Ion, Li-Polymer, and LiFePO4

batteries targeted at space-limited portable applications.The device has a single power output that charges the battery. The system load can be

placed in parallel with the battery, as long as the average system load does not prevent

the battery from charging fully within the safety timer duration. When the system load is

placed in parallel with the battery, the charge current is shared between the system and

the battery.

The device has four phases for charging a Li-Ion/Li-Poly battery: trickle charge to bring the battery voltage up to VBATSHORT, precharge to recover a

fully discharged battery, fast-charge constant current to supply the bulk of the charge, and

voltage regulation to reach full capacity.

In all charge phases, an internal control loop monitors the IC junction temperature and

reduces the charge current if an internal temperature threshold, TREG, is

exceeded.

The charger power stage and charge current sense functions are fully integrated. The

charger function has high accuracy current and voltage regulation loops, charge status

display, and automatic charge termination. The charge voltage and fast charge current are

programmable through external resistors. The precharge and termination current threshold

track the fast charge current setting.