The bq24157S 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
The IC 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.
Charge is terminated based on battery voltage and user-selectable minimum current level.
During normal operation, the IC automatically restarts the charge cycle if the battery voltage
falls below an internal threshold and automatically enters sleep mode or high impedance mode when
the input supply is removed. The charge status can be reported to the host using the
I2C interface. During the charging process, the IC monitors its junction
temperature (TJ) and reduces the charge current after
TJ increases to about 125°C. To support a USB OTG device, bq24157S can
provide VBUS (5.05 V) by boosting the battery voltage. The IC is available in 20-pin DSBGA