The document discusses operational amplifiers and Schmitt triggers. It defines a Schmitt trigger as a comparator that uses positive feedback, giving it distinct upper and lower threshold voltages. The document describes the inverting and non-inverting configurations of Schmitt triggers and provides mathematical expressions for calculating the threshold voltages. It compares the characteristics of comparators and Schmitt triggers, noting that Schmitt triggers can convert waveforms to square waves using positive feedback. The document was presented by an electrical engineering professor to explain operational amplifier applications.

1. By
Mr. C.R.Shinde
Electrical Engineering Department
Matoshri College of Engineering & Research centre, Nashik

2. Unit 04: Operational Amplifier Applications.
Unit 4_Module3
1. Introduction to Op-Amp
2. Op-Amp as zero crossing detector (ZCD) and comparator.
3. Op-Amp as Schmitt trigger.
4. Op-Amp as V-I and I-V converters.
5. Op-Amp as Instrumentation amplifier.
6. Waveform generation using Op-Amp - sine, square, saw
tooth and triangular generator.
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Matoshri College of Engineering & Research Center Nashik

3. Op-Amp as Schmitt trigger
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Matoshri College of Engineering & Research Center Nashik

4. Schmitt trigger
 Schmitt trigger is basically a “comparator”.
 In comparator no feedback is being used.
 When comparator used positive feedback is known as
“Schmitt trigger”.
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Matoshri College of Engineering & Research Center Nashik

5. Types of Schmitt trigger
1. Inverting Schmitt trigger.
2. Non- Inverting Schmitt trigger.
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Matoshri College of Engineering & Research Center Nashik

6. Two different triggering voltage are
define for Schmitt trigger
 Upper threshold voltage (V ut)
 Lower threshold voltage (V lt )
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Matoshri College of Engineering & Research Center Nashik

7.  The mathematical expression for Upper threshold voltage.
 The mathematical expression for Lower threshold voltage
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Matoshri College of Engineering & Research Center Nashik

8. Inverting Schmitt trigger.
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9. Non-Inverting Schmitt trigger.
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Nashik

10. PARAMETERS COMPARATOR SCHMITT TRIGGER
Use of feedback Feedback is not used Positive feedback is used
Trigger Level At zero volt or at the Vref. The upper and lower level
trigger have distinct values.
Output voltage The output voltage can be
+Vsat or –Vsat.
The output voltage can be
+Vsat or –Vsat.
Configurations Non-Inverting or Inverting
Comparator
Non- Inverting & Inverting
Schmiit trigger.
Application ZCD, Window Detector ,
Schmitt trigger
To convert any shape
waveform to square shape
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11. Thank you
Mr. C. R. Shinde
Electrical Engineering Department
Matoshri College of Engineering & Research centre, Nashik
If you have any query, ask me anytime on…… … .. . . .
cshinde58@gmail.com
chandrakant.shinde@matoshri.edu.in
9970031353
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Matoshri College of Engineering & Research Center
Nashik