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BQ24195: how to check battery short protection happening

Hardy Zhou
Intellectual 1650 points
Part Number: BQ24195

I want to know how BQ24195 check the battery short and can the BATFET be turned off automatically inside BQ24195?

Thanks

  • 0
    TI__Expert 8230 points
    Hello Hardy,

    You can use a battery emulator or sourcemeter on BAT and either apply a short between BAT or GND or while charging lower the voltage until it drops below the BAT_SHORT threshold (2V typical). If the battery voltage falls below 2V, the charge current is reduced to 100 mA for battery safety.

    On a real battery, the protection FETs would open from either the over-current protection or the under-cell voltage protection, most likely the OCP would trigger first.
  • 0 in reply to Fernando Lopez
    TI__Intellectual 1650 points
    this is for the charging, and when system works in OTG mode, and short the PMID to GND, how is the protection inside BQ24195 executed ?
    Thanks
  • 0 in reply to Hardy Zhou
    TI__Mastermind 25800 points
    Hey Hardy,

    There are a few things that can happen if the output is overloaded or shorted in OTG mode.

    One scenario is the over-current threshold is triggered (IBATFET_OCP) and the BATFET is turned off. This has a 9A minimum threshold. This protection is the same if the SYS output is drawing too much current in Battery Only Mode.

    Another scenario, the short will pull on the VBAT node below the OTG operating threshold, turning off OTG mode until the VBAT voltage climbs up again.

    Lastly, as Fernando mentioned in the previous post, a real battery will have protection FETs that may also trip if the short condition surpasses an Over-current or Short-current threshold.


    Regards,
    Joel H