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What is Schmitt trigger how it works?
A Schmitt Trigger is a comparator circuit with hysteresis implemented by applying positive feedback to the noninverting input of a comparator or differential amplifier. A Schmitt Trigger uses two input different threshold voltage level to avoid noise in the input signal.
What are the other names of Schmitt trigger?
A Schmitt trigger circuit is also called a regenerative comparator circuit. The circuit is designed with a positive feedback and hence will have a regenerative action which will make the output switch levels.
What kind of amplifier does a schmitt trigger use?
Op Amp based Schmitt Trigger Circuits Since a Schmitt trigger circuit is essentially an amplifier with positive feedback, it is possible to implement this setup using operational amplifiers or simply Op Amps. Depending on where the input is applied, the Op-Amp based circuits can be further divided into Inverting and Non-Inverting Schmitt Triggers.
How is the output of a schmitt trigger controlled?
As mentioned earlier, a Schmitt Trigger is basically a Bistable Circuit whose output states are controlled by the input signal. Hence, it can be used as a level detecting circuit. The following circuit shows a simple design of Transistor based Schmitt Trigger.
When does an op-amp trigger a comparator?
When operating an Op-Amp in the open loop mode, where a feedback is not used, for example, in a Basic Comparator Circuit, the very large open loop gain of the Op-Amp will cause the smallest of noise in the input voltage to trigger the comparator.
What causes dead band condition in Schmitt trigger circuit?
Since a comparator circuit with a positive feedback is used, a dead band condition hysteresis can occur in the output. When the input of the comparator has a value higher than Vupt, its output switches from +Vsat to -Vsat and reverts back to its original state, +Vsat, when the input value goes below Vlpt.