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Newtham's avatar
Newtham
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6 years ago
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MAX V GPIO State at Power-Off

If a MAX V has all of its voltage switched off, will the GPIO pins be in tristate? (Not during power-up or power-down, but when it's completely off.)

I ask because I am using the MAX V to control another IC, and I want to be able to control the IC with the MAX V or with an external header, for testing. The header would be in parallel with the MAX V GPIO lines. So, if I power off the MAX V, will I be able to communicate with the IC directly, without interference?

Thanks!

  • Rahul_S_Intel1's avatar
    Rahul_S_Intel1
    6 years ago

    If no power given to the device, the Impedance will be undefined, why I am saying so each IO pin can be considered active component and can be act as energy storage device. In my point of view , it is not safe to give to power off only Max 5 in a board.

4 Replies

  • Rahul_S_Intel1's avatar
    Rahul_S_Intel1
    Icon for Frequent Contributor rankFrequent Contributor
    6 years ago

    Hi ,

    If I understood correctly , if you loose the power of Max V , there will be no power on the IO pins

  • Newtham's avatar
    Newtham
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    6 years ago

    No, sorry if I wasn't clear.

    What is the input impedance of the GPIO pins when there is no power to the MAX V?

    Thanks

  • Rahul_S_Intel1's avatar
    Rahul_S_Intel1
    Icon for Frequent Contributor rankFrequent Contributor
    6 years ago

    If no power given to the device, the Impedance will be undefined, why I am saying so each IO pin can be considered active component and can be act as energy storage device. In my point of view , it is not safe to give to power off only Max 5 in a board.

  • Newtham's avatar
    Newtham
    Icon for New Contributor rankNew Contributor
    6 years ago

    OK, that makes sense. That's what I was wondering. Thank you!