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TCA9538: Check if the address pins (A0/A1) of TCA9538PW can be floating

Kevin Jiang1
Prodigy 60 points
Part Number: TCA9538

Hi,

I'd like to know if the address pins (A0/A1) of  TCA9538PW is floating, is there any side effect?

  • +1
    Prodigy 60 points

    Can we know if TCA9538PW support floating application for address pins?

  • 0 in reply to Kevin Jiang1
    TI__Guru 73651 points

    Hi Kevin,

    The TCA9538 (any of our IO expanders with address pins) will have the address pins in an unknown state when you leave them floating. 

    The device may not respond to read/writes or may change stop responding to read/writes due to a bias change on the address pins. I would expect the device to randomly work and randomly not work. You will also see higher consumption/supply current.

    In short, we do not recommend leaving the address pins floating due to higher supply current draw and intermittent operation of our device.

    -Bobby

  • 0 in reply to BOBBY
    Prodigy 60 points

    I don't have further questions and it's ok to close this ticket.

    Thanks for your clarification.