BQ24273

The bq24273 is a highly integrated single cell Li-Ion battery charger with integrated charge current sense element device targeted for space-limited, portable applications with high capacity batteries. The single cell charger operates from a dedicated power source such as a wall adapter or wireless power supply for a versatile solution. The integrated sense element eliminates the need for an external sense resistor reducing the total solution size and external component count.

The battery is charged in three phases: precharge, fast charge constant current and constant voltage. In all charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if the internal temperature threshold is exceeded. Charge is terminated based on user-selectable minimum current level. A software watchdog provides a safety backup for I2C interface while a safety timer prevents continuously charging a damaged battery. During normal operation, bq24273 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 is reported to the host using the I2C interface. Additionally, a voltage-based battery pack thermistor monitoring input (TS) is included that monitors battery temperature for safe charging. The TS function for bq24273 JEITA compatible.