# Non-monotonic signal crossing VIL and VIH

I'm using a logic buffer SN74LVC2G125 (SN74LVC2G125 datasheet) which is powered by 1.8V and has VIH and VIL of 1.17V and 0.63V, respectively.

If I have an input signal like below, could the buffer's output potentially toggle during time intervals B-C and E-F? If not, what are potential negatives that can result from non-monotonic signals crossing VIH and VIL?

• Am I reading this right that the input voltage is negative? You'll fry the chip; its absolute maximum limit on any input is no less than -0.5 volts. Jul 9, 2021 at 15:13
• @Hearth No, it's just a part of dashed line Jul 9, 2021 at 15:23

All that is guaranteed is that any voltage higher than $$\V_{IH}\$$ is interpreted as a high input, and any voltage lower than $$\V_{IL}\$$ is interpreted as a low input. All bets are off if $$\V_{IL}.
In all likelihood, there will be some voltage somewhere between $$\V_{IL}\$$ and $$\V_{IH}\$$ where the input toggles, but what that voltage is--or even whether that voltage is well defined--is not specified.