BQ24040DSQR

The BQ2404x series of devices are highly integrated
Li-Ion and Li-Pol linear chargers devices targeted at
space-limited portable applications. The devices
operate from either a USB port or AC adapter. The
high input voltage range with input overvoltage
protection supports low-cost unregulated adapters.
The BQ2404x has a single power output that charges
the battery. A system load can be placed in parallel
with the battery as long as the average system load
does not keep the battery from charging fully during
the 10 hour safety timer.
The battery is charged in three phases: conditioning,
constant current and constant voltage. In all charge
phases, an internal control loop monitors the IC
junction temperature and reduces the charge current
if an internal temperature threshold 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 charge termination.
The pre-charge current and termination current
threshold are programmed through an external
resistor on the BQ24040 and BQ24045. The fast
charge current value is also programmable through an
external resistor.