What are Schmitt Trigger logic gates?
Schmitt Trigger gates are devices used to convert imperfect, slow, or noisy signals into well-defined, fast, and noise-free digital signals. They perform the same logical functions as common gates but possess certain special distinctive features.

symbol Schmitt trigger
Their characteristics make them very useful in many applications where problems with poorly defined, distorted or noisy signals occur.

The gates operate like common gates but are characterized by having a property called hysteresis that makes them immune to noise and allows them to work with non-ideal digital signals. A Schmitt-trigger gate always delivers a square wave to the output, regardless of the waveform of the input signal.

Schmitt trigger

The hysteresis feature means that Schmitt-trigger devices only respond when the voltages applied to their inputs exceed preset limit values, called thresholds.