bq24157S Switch-Mode One-Cell Li-Ion Charger IC Texas Instruments bq24157S Switch-Mode One-Cell Li-Ion Charger IC is a compact, flexible, high-efficiency, USB-friendly switch-mode charge management device for single-cell Li-ion and Li-polymer batteries used in a wide range of portable applications. The charge parameters can be programmed through an I2C interface. The IC integrates a synchronous PWM controller, power MOSFETs, input current sensing, high-accuracy current and voltage regulation, and charge termination, into a small DSBGA package. The Texas Instruments bq24157S charges the battery in three phases: conditioning, constant current, and constant voltage. The input current is automatically limited to the value set by the host. The charge is terminated based on battery voltage and user-selectable minimum current level. A safety timer with reset control provides a safety backup for the I2C interface.