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SN74AHC1G00: wrong VIH threshold

Part Number: SN74AHC1G00

Tool/software:

Hi team, 

My customer is using SN74AHC1G00DCKR for logic function and met wrong VIH threshould.

Issue: They connect pinA and pinB together and when input signal is up to 1.1V and then output will down to 0V. VIH is 2.1Vmin in datasheet.

Blue is VCC. Yellow is input signal. Green is output. when input signal is up to 1.1V. Output goes down to 0V. It is unreasonable.

There is only one case. We can not confirm the batch and top mask is AAJ.

Could we submitted a PA request on TI.com?

  • Input voltages of VIH or higher are guaranteed to be read as high.
    Input voltages of VIL or lower are guaranteed to be read as low.
    For input voltages between VIL and VIH, the behaviour is undefined. Switching at 1.1 V is allowed.

    Please note that this input signal violates the Δt/Δv limit. You would need a device with Schmitt-trigger input to handle this signal. But if you want a well-defined switching threshold, you need to use a comparator.