The BQ25012RHLR is a 1-cell Li-Ion/Polymer linear charger IC from Texas Instruments. Its 500 mA max charge current sets the charge-rate ceiling for the battery. The USB interface means the part can draw power directly from a USB host or wall adapter without an external DC-DC stage — the 6.5 V supply max covers the 5 V USB bus with margin.
Programmable features and protection
Charge current and charge timer are programmable via external components, giving the designer control over the charge profile without an I2C bus. The constant-current constant-voltage algorithm terminates at 4.2 V battery pack voltage. Fault protection includes over-temperature shutdown, and the junction is rated to 125°C — useful when the charger sits near a processor or power amplifier in a sealed enclosure.