This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

SN7400: SN74LVC14APWR

Part Number: SN7400

Tool/software:

TI Customer Support Center representative:


Thank you for your help.

I am using your product, SN74LVC14APWR.
This is an IC with six Schmitt trigger type inverters, and I am using two of the six inverters, one each in circuit A and circuit B.
It would be a problem if circuit A and circuit B stopped working at the same time, so I would appreciate it if you could confirm the following.

Question 1) When Vcc = 0V
When power is no longer supplied to the SN74LVC14APWR (i.e., when Vcc = 0V),
will the internal inverters be open or short-circuited?

Question 2) When Vcc = Overvoltage
If an overvoltage is applied to the SN74LVC14APWR (for example, when Vcc = 1000V),
will the internal inverters be open or short-circuited?

Question 3) Failure mode in which the internal inverters are simultaneously disabled
Are there any failure modes other than 1) and 2) above in which the internal inverters are simultaneously disabled?

Thank you in advance for your help.

  • Hi Yoshinori,

    I'm reaching out to the test team to see if we have any official documentation on this to send you and will let you know when I get that back.

    1. Vcc = 0: The output here is undefined. The internal logic of this part was not designed to operate with a voltage at the input when VCC = 0. We have some parts that enter a high impedance mode in this case, but this one does not. It is possible that the device could be open or short circuited to ground or VCC, and it is possible that the behavior is not consistent across devices. This is really where I need to confer with the testing team.

    2. Vcc = Overvoltage. This part has a protection diode that runs between the output and VCC. When VCC is large enough, the diode will break and the output will short to VCC.

    3. The only case that comes to mind is Vcc= undervoltage. If the VCC is low enough below the absolute minimum VCC, the outputs and inputs will short to GND.

    Hope this helps!

    Ian