This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ25756: I2C controls battery and device current distribution

Part Number: BQ25756
Other Parts Discussed in Thread: BQ25750

We have learned that this chip has a charging mode controlled by a 2C host, and my current switching power supply is limited by its size, so the power cannot be increased. Please help confirm if BQ25756 can adjust the charging current size through the I2C protocol. For example, when inserting an external power source and simultaneously connecting the device and battery, the power source prioritizes supplying power to the device, and the remaining power is then supplied to the battery. The charging current of the battery is 1A;

When the device is unplugged, the power supply charges the battery according to the maximum charging current of the charging IC, which is 3A. Is this function implemented through the I2C interface settings.

  • Hi HY,

    BQ25756 does not have powerpath to separate the system load (device) and battery.  So, the system load and battery are in parallel.  The charger provides up to the maximum output/charge current, with the system load having priority if attached.  Any remaining current goes to charge the battery. When the input power source goes away, the system is power from the battery.

    BQ25750 has traditional powerpath where the system (device) and charger are powered directly from the input power source, with the system having priority if attached.  When the input power source goes away, the battery FETs turn on so that the system is powered from the battery.

    Both function as explained above using external resistors for default settings with I2C.

    Regards,

    Jeff