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[CDCE62002, CDCE62005] Tri-state outputs, Pull up resistors on CDCE62005 EVM

Benjamin Mak
Intellectual 2190 points
Other Parts Discussed in Thread: CDCE62002, CDCE62005

Hi Team!

I wanted to confirm the following things on the CDCE62002 and CDCE62005:

  1. Are the outputs of CDCE62002 and the CDCE62005 tri state outputs? I believe the MISO output is. Can someone confirm this?
  1. If so, should we have pull-ups or pull-downs for these outputs? I think the MISO has a pull-up typically.
  • Also, what is the reason for having a pull-up on SPI interface on the CDCE62005 EVM? I understand that on the MISO line it might be good to have one in the event of start up or something of that nature. I also see that the other SPI lines have internal pullups.

Thank you for your support!

Ben

  • 0
    TI__Mastermind 20900 points

    Hello Ben,

    1. yes the MISO output is a tri state output. All other outputs can be configured to tri state by setting to disable.

    2. please use the recommended schematic from the EVM.

    • pull ups are present in the SPI interface, that they have defined levels at start up.

    Best regards,

    Julian

  • 0 in reply to Julian Hagedorn
    TI__Expert 5055 points

    Hi Julian,

    Thanks for the input. Two things to clarify:

    1) Is this common practice with SPI to use pull-ups to ensure known-good state, or is it a "feature" of our part?

    2) The CDCE62002 datasheet says MISO is Open Drain. If this is an error, can we edit the datasheet?

     

    Thanks,

    Bryan, Sunnyvale Field Apps