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SN74LVC08A: Without output protection diode

Beat Sigrist
Prodigy 10 points
Part Number: SN74LVC08A

I am searching for a 1:1 replacement of the component SN74LVC08APWR.
In a special operation case (not normally / not recommended but sill possible for the users perspective) it is possible that some current flows from the SN74LVC08A device GND to the Output.
If my whole device has a floating negative power supply, and on the same time the the device GPIO (signal-name IO.2) is connected to GND, then the system starts to run.
The current flows from the D-GND through the output protection diode of U37C and than trough the input protection of T20 and then through the body diode of T20 (see picture).
So I am searching for a 1:1 pin compatible replacement of the SN74LVC08APWR without an output protection diode
.

  • 0
    Guru 246890 points

    The substrate of this chip (and of any other logic device) is made of p-type silicon, and forms parasitic diodes with n-type silicon, i.e., with all transistors, diodes, and other components. It is not possible to remove the GND diode from the output.