BQ24027EVM [Texas Instruments]

The bqTINY-II series offers integrated USB-port and ac-adapter supply management with autonomous power-source selection, power FET and current sensor, high-accuracy current and voltage regulation, charge status, and charge termination in a single monolithic device. It automatically selects the USB-port or the ac-adapter as the power source for the system. In the USB configuration, the host can select from two preset charge rates of 100mA and 500mA. In the ac-adapter configuration, an external resistor sets the magnitude of the system or charge current. The bqTINY-II charges the battery in three phases: conditioning, constant current, and constant voltage. Charge is terminated based on minimum current. An internal charge timer provides a backup safety for charge termination. The bqTINY-II automatically restarts the charge if the battery voltage falls below an internal threshold. The bqTINY-II automatically enters sleep mode when both supplies are removed.