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Schmitt trigger VS. Inverter

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JackyH

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I have a question regarding the Schmitt trigger . It seems like Schmitt trigger is often used in integrated circuit to obtain a steep signal

But a simple inverter can also do this job, to make the output signal have a steep transition

I want to know more about Schmitt trigger ,normally when do people apply Schmitt trigger instead of inverter?
 

You use a Schmidt-trigger (S-T) when de input signal is not going directly from 0 to 1 (or 1 to 0 ) but slowly or with a 'bump'. The S-T prefents false data transitions.
See picture:

65_1190834766.jpg


(input signal)
(output signal without S-T)
(output signal with S-T)
 

    J

    JackyH

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ST are used when the circuit mix analog with digital signals.
It is very important if you design circuits based on syncronous philosophy.

+++
 

    J

    JackyH

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schmitt triggers are used when the input is noisy.... i.e. the input may cause multiple transitions if given to a ordinary comparator...
 

    J

    JackyH

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So every digital input I/O first stage is Schmitt Trigger inverter for noise cancellation.
 

    J

    JackyH

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Sometimes, the input voltage is not ground or supply level. For inverter, it will be a large quiescient current while it is not the case for schmitt trigger.
 

    J

    JackyH

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eleminate the noise
 

    J

    JackyH

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