BQ24156A,pdf(Fully Integrated Switch Mode One Cell Li-Ion Ch

The bq24153A/6A/8 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 WCSP package.
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. A safety timer with reset control provides a safety backup for I2C
interface. 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 once TJ increases to about 125°C.
To support USB OTG device, bq24153A/8 can provide VBUS (5.05V) by boosting the battery voltage. The IC is
available in 20-pin WCSP package.