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Linux/BQ25898: power off mode implementation

Dharmender Sharma
Prodigy 80 points
Part Number: BQ25898
Other Parts Discussed in Thread: BQ25890,

Tool/software: Linux

Hi ,

i am porting bq25890 to bq25898 driver.

i am facing one problem , when i press the power off button and after some time is see that system is still getting power from battery.

so my question is how to stop power from battery to system if we press the power off button?

is power mode is already taken care by PMIC?

Thanks & Best regards,

Dharmender SHarma

  • 0
    TI__Guru 57341 points
    Hi,

    Referring to 9.2.2, if only battery is present and the voltage is above depletion threshold (VBAT_DPLZ), the BATFET turns on and connects battery to system.
    Referring to 9.2.10.1, to extend battery life and minimize power when system is powered off during system idle, shipping, or storage, the device can turn off BATFET so that the system voltage is zero to minimize the battery leakage current. When the host set BATFET_DIS bit (REG09[5]), the charger can turn off BATFET immediately or delay by tSM_DLY as configurated by BATFET_DLY bit(REG09[3]).

    Thanks,

    Ning
    Please click "This Resolved my issue" button if this post answer your question.
  • 0 in reply to Ning T
    Prodigy 80 points
    Hi,

    thanks for information.

    i am writing 0x24 on reg09 which disable the power from battery. but when i press power button again then system is not coming up.

    when i remove the bettery and attach again and then press the power button then system is coming up.

    so i do not know why this is happening?

    Thanks & Best regards,
    Dharmender SHarma
  • 0 in reply to Dharmender Sharma
    TI__Guru 57341 points
    Hi,

    Could you please write REG09=2C instead of 24 then try again?

    Thanks,

    Ning
    Please click "This Resolved my issue" button if this post answer your question.
  • 0 in reply to Ning T
    Prodigy 80 points
    Hi,

    i tried 2c also but still noticing the same behavior.

    Thanks & Best Regards,
    Dharmender Sharma
  • 0 in reply to Dharmender Sharma
    TI__Guru 57341 points
    Hi,

    What you mean "press the power button" exactly? Referring to 9.2.10.2 BATFET Enable (Exit Shipping Mode) on the d/s,

    When the BATFET is disabled (in shipping mode) and indicated by setting BATFET_DIS, one of the following events can enable BATFET to restore system power:
    1. Plug in adapter
    2. Clear BATFET_DIS bit
    3. Set REG_RST bit to reset all registers including BATFET_DIS bit to default (0)
    4. A logic high to low transition on QON pin with tSHIPMODE deglitch time to enable BATFET to exit shipping
    mode

    Thanks,

    Ning
    Please click "This Resolved my issue" button if this post answer your question.
  • 0 in reply to Ning T
    Prodigy 80 points
    Hi ,

    Thanks for answer. the above information resolve my issue. i will see how i can implement solution 4 i.e A logic high to low transition on QON pin with tSHIPMODE deglitch time to enable BATFET to exit shipping
    mode

    Regards,
    Dharmender Sharma
  • 0 in reply to Dharmender Sharma
    TI__Guru 57341 points
    Hi,

    It's great that you are able to resolve the issue. This thread is considered closed.

    Thanks,

    Ning.