Texas Instruments bq25792 Switch-Mode Buck-Boost Chargers

The chargers support narrow VDC (NVDC) power path management, in which the system is regulated at a voltage slightly higher than the battery voltage but does not drop below the minimum system voltage. The system keeps operating even when the battery is completely discharged or removed. When load power exceeds the input source rating, the battery gets into supplement mode, preventing the input source from overloading and the system from crashing.

The devices charge a battery from a wide range of input sources, including legacy USB adapters, high-voltage USB-PD adapters, and traditional barrel adapters. The charger seamlessly transitions among buck, boost, or buck-boost configurations based on input voltage and battery voltage without the host's control. The optional dual input source selector manages the power flowing from two different input sources. The host controls the input source selection through I²C by prioritizing the first available input source.

The Texas Instruments bq25792 switch-mode buck-boost chargers provide various safety features for battery charging and system operations, including battery temperature negative thermistor (NTC) monitoring, trickle charge, pre-charge, and fast charge timers and overvoltage/overcurrent protections on the battery and the charger power input pin. The thermal regulation reduces the charge current when the die temperature exceeds a programmable threshold. The STAT output of the device reports the charging status and any fault conditions. The INT pin immediately notifies the host when a fault occurs.

The devices also provide a 16-bit analog-to-digital converter (ADC) for monitoring charge current and input/battery/system voltages, the TS pin voltage, and the die temperature. The components are available in a WCSP 2.9mm x 3.3mm 56-pin package.