The BQ24800 device is a high-efficiency, synchronous buck battery charger, offering low component count for space-constrained, multi-chemistry battery charging applications.
The BQ24800 device supports hybrid power boost mode. Hybrid power boost mode boosts the battery up to the system voltage in order to supplement the adapter when system power demand is temporarily higher than the adapter is able to provide. The ultra-fast transition from battery charging to battery discharging prevents adapter crash from overloading condition.
The BQ24800 device also supports battery only boost mode when no adapter is present. When the battery voltage is above the minimum system operation voltage, the battery is directly connected to the system supply rail through BATFET. Once the battery voltage goes below the minimum system operation voltage, BQ24800 will turn on the boost mode to regulate the system supply rail, extending the system run time.
The BQ24800 device uses two charge pumps to separately drive N-channel MOSFETs (ACFET, RBFET, and BATFET) for automatic system power source selection.
Through SMBus, a system power management microcontroller programs input current, charge current, discharge current, and charge voltage DACs with high regulation accuracies.
The BQ24800 device monitors adapter current (IADP), battery discharge current (IDCHG), and system power (PMON) for host to throttle back CPU speed or reduce system power when needed.
The BQ24800 device charges 1-, 2-, 3-, or 4-series Li+ cells.