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Original question:

BQ25890: Status pin function disable

BQ25890: Stop STAT pin function

Gary Teng
Genius 5520 points
Part Number: BQ25890
Other Parts Discussed in Thread: BQ25892

Hi Sir,

 We've discussed STAT pin function at BQ25890 earlier. Customer still has problem in stoping STAT pin function currently at their board and EVM.

 They want to stop STAT pin blinking function at VBus input and without battery. They've test below setting but still can't stop blinking:

Bit 4 at REG03: 0

Bit 6 at REG07: 1

Bit 4/5 at REG07: 0

  Is there any setting they have to take care for stop STAT pin function?

Thanks and regards,

Gary Teng

  • 0
    TI__Mastermind 26050 points

    Hi Gary, 

    I have tested on BQ25890EVM again to re-confirm.

    With no battery attached and VBUS input using I2C write to either set charge disable (REG03 bit 4 = 0) or STAT pin disable (REG07 bit 6 = 1) function to stop STAT pin blinking. Disabling watchdog timer as well ensures STAT LED will remain off. 

    The report of stat pin still blinking after the register settings you list indicates customer is not performing the I2C writes correctly. Please advise customer to ensure their I2C communication is functioning properly. 

    Best Regards,

    Garrett 

  • 0 in reply to Garrett Kreger
    Prodigy 30 points

    Hi Garrett
    The following are the test results on our side,
    With battery attached and VBUS input using I2C write to either set charge disable or enable (REG03 bit 4 = 0 or 1 ) or STAT pin disable or enable (REG07 bit 6 = 1 or 0) function to stop or enable STAT pin is no problem,,
    indicating that I2C can be executed correctly.

    But with no battery attached, these settings are useless and STAT pin blinking cannot be stopped.

    Please provide the setting values ​​of all registers in EVB for us to confirm.
    I can't think of any difference between us, could you provide other confirmation methods to figure out the cause of the problem?
    Best regards
    Kevin

  • 0 in reply to Kevin Chen
    TI__Mastermind 26050 points

    Hi Kevin, 

    Please see the below. 

    The first image shows all register settings on the EVM in both binary and hex. All settings should be default besides WATCHDOG, STAT_DIS, and CHG_CONFIG. 

    The second image shows the hardware setup in lab. As you can see I have nothing connected at BAT pin and STAT pin blinking is stopped via I2C write. 

    I recommend you first attempt to match my results on the EVM board. When you see STAT pin continue blinking have you confirmed with I2C reads that register values are as you expected? I wonder if something such as an unstable input supply is causing registers to reset to default and therefore result in STAT pin blinking with no battery attached. 

    Best Regards,

    Garrett 

  • 0 in reply to Garrett Kreger
    Prodigy 30 points


    Hi Garrett
    Need your help to confirm the JP10 jumper on EVB.
    In the state of without Battery, it also means that the TS is faulty, should the JP10 jumper be opened?

    Please help confirm the results of JP10 open.
    Best regards
    Kevin

  • 0 in reply to Kevin Chen
    TI__Mastermind 26050 points

    Hi Kevin,

    You are correct that removing JP10 on EVM will be the same as the NTC being removed along with the battery. 

    With this setup clarification I have the same observation as you. The STAT pin blinking indicating a TS fault does not stop when STAT_DIS = 1. 

    I found documentation which unfortunately confirmed this is known behavior on BQ25890 device. STAT_DIS = 1 will disable STAT pin from driving either high or low, but it will not stop STAT pin blinking for a TS fault. I apologies for this inconvenience. 

    Best Regards,

    Garrett 

  • 0 in reply to Garrett Kreger
    Prodigy 30 points

    Hi Garrett
    Thanks for your reply.
    This result indicates that the behavior "STAT pin blinking for a TS fault" has the highest priority.
    Please help provide documentation to prove that this behavior cannot be changed.
    Best regards

  • 0 in reply to Kevin Chen
    TI__Mastermind 26050 points

    Hi Kevin, 

    I do not have dedicated documentation on this behavior available to share, but unfortunately the behavior cannot be modified. Below I have attached a previous E2E thread from years ago confirming the same behavior is expected on BQ25892, which shares a datasheet and is very similar to the BQ25890. 

    https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/726462/bq25892-stat_dis-bit-does-not-disable-status-pin 

    Best Regards,

    Garrett