4.5A Switch-Mode Battery Charge Management

The bq24190, bq24192, bq24192I, and bq24193 are highly-integrated switch-mode battery charge management and system power path management devices for single cell Li-Ion and Li-polymer battery in a wide range of tablet and other portable devices. Its low impedance power path optimizes switch-mode operation efficiency, reduces battery charging time and extends battery life during discharging phase. The I2C serial interface with charging and system settings makes the device a truly flexible solution.

The device supports a wide range of input sources, including standard USB host port, USB charging port and high power DC adapter. To set the default input current limit, the bq24190 detects the input source following the USB battery charging spec 1.2, and the bq24192, bq24192I, and bq24193 takes the results from detection circuit in the system, such as USB PHY device. The bq24190,192,192I, and 193 are compliant with USB 2.0 and USB 3.0 power specifications with input current and voltage regulation. Meanwhile, the bq24190, bq24192, bq24192I, and bq24193 meets USB On-the-Go operation power rating specification by supplying 5V on the VBUS with a current limit up to 1.3A.

The power path management regulates the system slightly above battery voltage but does not drop below 3.5V minimum system voltage (programmable). With this feature, the system maintains operation even when the battery is completely depleted or removed. When the input current limit or voltage limit is reached, the power path management automatically reduces the charge current to zero. As the system load continues to increase, the power path discharges the battery until the system power requirement is met. This supplement mode operation prevents overloading the input source.

The devices initiate and complete a charging cycle without software control. It automatically detects the battery voltage and charges the battery in three phases: pre-conditioning, constant current and constant voltage. At the end of the charging cycle, the charger automatically terminates when the charge current is below a preset limit in the constant voltage phase. When the full battery falls below the recharge threshold, the charger will automatically start another charging cycle.

The bq24190, bq24192, bq24192I, and bq24193 provide various safety features for battery charging and system operation, including dual pack negative thermistor monitoring, charging safety timer and over-voltage/over-current protections. The bq24193 supports JEITA guideline compliant temperature profile. The thermal regulation reduces charge current when the junction temperature exceeds 120°C (programmable).

Source: http://www.ti.com/product/bq24190?DCMP=hpa-pmp-battery-bq2419x-en&HQS=bq24190-pr