This document discusses the use of the IC 555 timer chip for astable and monostable multivibrators and as a sequence generator. It begins with an introduction to multivibrators and their classifications. Then it explains the functional blocks of the IC 555 chip. Next, it describes how to configure the IC 555 as an astable multivibrator that switches between two states and as a monostable multivibrator that has one stable state. Finally, it briefly mentions using the IC 555 as a sequence generator.

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

2. Unit 05: Other Analog circuits:-
1. Active filters-Its configuration with frequency response
2. Analysis of first order low pass and high pass filters using OPAMP.
3. IC 555 –construction, working .
4. IC 555 –astable and monostable multi vibrators, Sequence generator
5. voltage regulators using IC78xx, 79xx, LM 317
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Matoshri College of Engineering & Research Center Nashik
Unit 5_Module4

3. IC 555 –astable and monostable multi
vibrators, Sequence generator
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Matoshri College of Engineering & Research Center Nashik
Unit 5_Module4

4. Content.
1. Introduction to Multivibrator.
2. IC-555 as Astable Multivibrator.
3. IC-555 as Monostable Multivibrator.
4. IC-555 as Sequence Generator.
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5. Introduction to Multivibrator.
 Multivibrator is an electronics circuit which can have no,
one or two stable state of operation.
 Depending on the number of stable state we can classify
the multivibrator as shown below.
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Multivibrator
Astable Monostable Bistable

6. Functional Block Diagram of IC 555
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7. IC-555 as Astable Multivibrator.
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Case 1 :- Charging of Capacitor.
Case 2 :- Discharging of Capacitor.
Voltage on pin no2(Trigger)
is less than 1/3Vcc
Voltage on pin no 6 (Threshold)
is reached to 2/3Vcc

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T= Tc + Td f = 1 / T

10. IC-555 as Monostable Multivibrator.
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Case 1 :- Charging of Capacitor.
Case 2 :- Discharging of Capacitor.
Voltage on pin no2(Trigger) is
high then capacitor start
charging.
Voltage on pin no 6 (Threshold)
is reached to 2/3Vcc

11. Tc=1.1RC
Td = 0
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13. 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
Unit 5_Module4