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BQ25792: About operation when the watchdog timer expires

Part Number: BQ25792
Other Parts Discussed in Thread: BQ25798

Hi,

Please tell me about the watchdog timer.
Will BQ25792 stop charging if the watchdog timer expires?
Or will BQ25792 continue to charge?

I understand that the registers will be reset.
However, the EN_CHG bit after reset is 1.
Does this mean to continue charging?



Regards,
Yusuke



  • Hi Yusuke-san,

    Yes.  The EN_CHG bit is reset to default setting of 1 after watchdog timer expires.  If your customer does not want charging after timer expires, then I recommend using the /CE pin to disable charge.

    Regards,

    Jeff

  • Hi Jeff-san,

    Thank you for your response.
    >The EN_CHG bit is reset to default setting of 1 after watchdog timer expires. 

    Could you tell me why TI didn't design the WD to stop charging when it expires?
    Was there a demand to continue charging with the default settings after it expired?

    Customer sets the charge voltage setting to a lower charge voltage than the default.
    In that background, customers want to know why CHG bit is set to 1.

    Regards,
    Yusuke

  • Hi Yusuke,

    Almost all of TI's chargers have this configuration.  Few customers have complained. We added a new bit (REG0x09b5=1) in the BQ25798 that allows the host to force EN_CHG=0 when WD timer expires.   Unfortunately, the BQ25798 datasheet currently on the web does not show this bit. I am working to get datasheet updated.

    Regards,
    Jeff