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BQ78Z100: Wakeup Help for One Wire BQ Parts GENERAL

Steve Carkner
Prodigy 80 points
Part Number: BQ78Z100
Other Parts Discussed in Thread: BQ40Z50-R2, BQ28Z620

Tool/software:

I have a need for a one-wire communication battery manager for a 2S pack that ALSO will wake up under a certain condition.

The BQ78Z100 can be setup to switch off after 1 minute of no communication.

But there is no way to wake it back up based on the communication line, instead a positive voltage must be applied to the Pack+

Are there ANY one wire interface chips that would, for example, leave the HDQ line weakly pulled up when the pack is off, so that pulling down the line would wake the pack back up?

It would be like having the /PRES line of an SMBus battery pack being shared with the HDQ line.

Other suggestions for making a one-wire communication battery pack that can be woke up and put to sleep using only that one wire would be appreciated.

We have at least a dozen battery systems already using TI chips, so our preference is to stay with TI.

  • 0
    TI__Mastermind 26595 points

    Hello Steve,

    This question has been assigned and will be process when possible.

    Thank you,
    Alan 

  • 0
    TI__Mastermind 26595 points

    Hello Steve, 

    Seeing how your requirements is for a 2S pack that narrows down the list to BQ28Z620 and the BQ40Z50-R2. In terms of one wire interface both of these units are able to be "turned on" when certain current/load are sense on the battery gauge configurable with the software. However the BQ40Z50-R2 is the only IC out of the two that has a pin called PRES or SHUTDN that is able to act like a physical button/signal that can be used. If this doesn't fit your system than please look into the link below to explore the different battery gauges offered.

    Battery fuel gauge:
    https://www.ti.com/battery-management/fuel-gauges/overview.html


    Thank you,
    Alan

  • 0 in reply to Alan Frias
    Prodigy 80 points

    I don't think you fully understood the question / requirement - I really want just ONE digital pin on the battery pack that handles all communication as well as the wakeup function. Everything is operated through that one single wire.

    There is a part from your competitor that perfectly meets this need (not sure if I am allowed to post competitor parts here?!?!?) - but since I have been using TI parts for 30 years, I was really hoping to stay with you.

    I don't see how the Z620 or Z50 could be made to work with just one single wire.

    I hope this helps.