Tool/software:
I am using the AND gate chip SN74AUP2G08DCUR. Due to circuit design problems, the input port has a negative voltage exceeding -1V.
The SN74AUP2G08 datasheet shows the input clamp current parameter(VI<0, IIK -50mA MAX).
So my conclusion is: the SN74AUP2G08 input port has a clamp diode, and the input port can withstand a negative voltage greater than -0.5V. For example, the negative voltage of -5V in the figure below, considering the clamp diode voltage drop, the clamp diode current does not exceed 50mA, and the AND gate still works normally at this time, and the AND gate input is judged as a low level.