Operational Amplifier as a Schmitt Trigger
The Schmitt trigger works as a threshold switch that turns on the output voltage at a certain input voltage which we call the upper threshold voltage (VUT) and turns off the output voltage at a certain input voltage lower threshold voltage (VLT).
Non-inverting Schmitt trigger
The function of a non-inverting Schmitt trigger can be well shown by the example of a sine-square converter:
Non-Inverting Schmitt Trigger Function Switching Behavior Hysteresis
Note: Since both curves have the time axis t as a common axis, they can be combined to form a so-called hysteresis characteristic curve from which the symbol of the Schmitt trigger is derived.
Circuit and calculation Op-Amp as a non-inverting Schmitt trigger
Non-Inverting Schmitt Trigger circuit
How to determine the upper threshold voltage (VUT)
Inverting Schmitt trigger
The function of an nverting Schmitt trigger can be well shown by the example of a sine-square converter:
Inverting Schmitt Trigger Function Switching Behavior Hysteresis