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TPS25730: Dead Battery Flag

Thomas Fink
Prodigy 75 points
Part Number: TPS25730
Other Parts Discussed in Thread: TPS25751

Tool/software:

Hi team,

how to clear the dead battery flag for the TPS25730 trough I2C as described in datasheet? In the regsister map I can't find any possibility.

I want to use the SINK_EN output signal to initiate a fast role swap on the host port of my usb hub when power is disconnected from the battery port which uses the TPS25730.

If the TPS25730 was powered up with 3V3 already available the SNK_EN Signal is activated (high) about 12ms after the plug is removed again.
If the TPS25730 was powered up in dead battery mode (3V3 from internal LDO) the SNK_EN Signal is activated about 40ms after the plug is removed which is too long in my application.

So i want to manually clear the dead battery flag if possible in case of dead battery startup to get a fast response if the plug is removed again.

Is that possible or is it described wrong in datasheet?

Thanks.

  • 0
    TI__Mastermind 37855 points

    Hi Thomas,

    There is currently not a way to clear the dead battery flag on the TPS25730.

    Thomas Fink said:
    Is that possible or is it described wrong in datasheet?

    Yes, it is described wrong in the datasheet. This section may have come from a similar part that does have this capability(clearing the dead battery flag).

    Unfortunately, unless you can guarantee 3.3V on VIN3V3 first, I do not think we have a good solution for improving the SINK_EN activation time for your use case.

    I would recommend exploring the PLUG_EVENT GPIO as that may have behavior similar to what you are looking for.

    Thanks and Regards,

    Chris

  • 0 in reply to Christopher Lim1
    Prodigy 75 points

    Hi Chris,

    I already checked the PLUG_EVENT GPIO - same problem there after dead battery startup.
    Do you have any suggestion for detecting the disconnection at the battery port as I need this to trigger a FRS for the host port?

    I need a trigger as soon the voltage on VBUS of the battery port beginns to fall. VBUS can be 5V/9V/15V/20V. Are there any chips available to do this job?

    Thanks.

    Kind Regards,

    Thomas

  • 0 in reply to Thomas Fink
    TI__Mastermind 37855 points

    Hi Thomas,

    Thomas Fink said:
    I already checked the PLUG_EVENT GPIO - same problem there after dead battery startup.
    Do you have any suggestion for detecting the disconnection at the battery port as I need this to trigger a FRS for the host port?

    Unfortunately, no, I cannot think of anything else that can be done with the TPS25730 to to gain a faster response time.

    Thomas Fink said:
    I need a trigger as soon the voltage on VBUS of the battery port beginns to fall. VBUS can be 5V/9V/15V/20V. Are there any chips available to do this job?

    The TPS 25751 would be the best option. The TPS25751 is a DRP part in the same family as the TPS25730. It has configurable GPIOs with similar behavior, and more importantly has the ability to clear the dead battery flag.

    Thanks and Regards,

    Chris