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ADS7809 model or info needed

John Aschenbrenner
Prodigy 30 points
Other Parts Discussed in Thread: ADS7809

Hello,

I'm working on a design that includes an ADS7809. The datasheet includes timing information such as the delay from clock to data valid, but it does not specify what test load was used to make the measurement. Does anyone know what the test load is?

Alternately, if there is an IBIS model of the part that would be even better. There isn't one published on the TI website.

Thanks a lot, 

John Aschenbrenner

AEi Systems

Los Angeles

  • 0
    Prodigy 30 points

    Can anyone help? I know that the ADS7809 is an old part so it can be hard to find information about it.

    -John

  • 0 in reply to John Aschenbrenner
    TI__Expert 5705 points

    Hi John,

    I apologize for the delayed response. Yes, the ADS7809 is an ancient part and unfortunately there is not a lot of information available on how the digital timing was characterized on this part. The datasheet does provide some limited information such as loading conditions for measuring driver logic levels and parasitic load at the output pins that you may find useful. Please let me know if you need additional information and I will see what I can come up with.

    Thanks,
    Harsha

  • 0 in reply to Harsha Munikoti
    Prodigy 30 points

    Thanks for your response. Yes, I see the output capacitance, but I don't see "loading conditions for measuring driver logic levels" anywhere. That's what I'm looking for.

    Thanks a lot,

    John

  • 0 in reply to John Aschenbrenner
    TI__Expert 5705 points

    Hi John,

    For VOL and VOH testing, the datasheet specifies using constant current loads of 1.6mA (pullup) and 500uA (pulldown) respectively. The part's digital driver must drive its output,  against these loads, to a value below VOL upper spec or above VOH lower spec, as the case may be. This information is in the highlighted portion of the datasheet snapshot I sent you earlier.

    Thanks,
    Harsha