Digital Electronics

1. PRESENTATION ON TOPIC :
CLIPPERS AND CLAMPERS
CIRCUITS &
NAND REALIZATION OF ALL
CIRCUITS
BY: ABHISHEK VISHWAKARMA
ECE-1
(1900270310008)

2. ABOUT COLLEGE
Ajay Kumar Garg Engineering College (AKGEC), Ghaziabad is affiliated to Dr. A.P.J. Abdul
Kalam Technical University, Lucknow, and is approved by the All India Council for
Technical Education. The college was established in 1998 and offers B.Tech courses in ten
disciplines of Engineering namely Computer Science and Engineering, Information
Technology, Computer Science, Computer Science & Information Technology, Computer
Science and Engineering (Artificial Intelligence & Machine Learning). Computer Science
and Engineering (Data Science), Electronics and Communication Engineering, Electrical
and Electronics Engineering, Mechanical Engineering and Civil Engineering. B.Tech
programs in Computer Science and Engineering, Information Technology, Electronics and
Communication Engineering, Electrical and Electronics Engineering and Mechanical
Engineering are accredited by NBA. At the post graduate level, the College offers M.Tech
in Electronics & Communication Engineering, Computer Science, Electrical and Electronics
Engineering and Mechanical Engineering and the Master of Computer Applications course.
The College also offers Bachelor of Vocation (B.Voc) course in two disciplines namely
Automobile Servicing and Production Technology. The college is accredited by NAAC.

3. ABOUT DEPARTMENT
Department of Electronics and Communication Engineering at AKGEC was established in
1998. The department provides an outstanding research environment complemented by
excellence in teaching. Ever since its inception, the department has been a pioneering
academic centre for higher education, research, and innovation in all major areas of
Electronics and Communication Engineering.
The Electronics and Communication stream represents two fastest growing technology
areas in view of exponential growth taking place in the communication networks in the
country. The department is organized in tune with these latest developments in terms of
curriculum, well-qualified faculty and the state-of-the-art labs for B.Tech. course in
Electronics & Communication Engineering along with M.Tech. course in Electronics &
Communication Engineering. Intake of B.Tech. (ECE) course is 180 students and for the
M.Tech. course it is 18 students. The department has its technical society-Phoenix. The
society organizes quizzes, technical seminars, mock interviews, aptitude tests and
technical paper presentation etc for the students. B.Tech. ECE is accredited by National
Board of Accreditation (NBA).

4. INDEX:-
 Clipper Circuits(Series and Parallel, Positive and
Negative)
 Clamper Circuits(Positive and Negative)
Implementation:(Live on Multisim)
 NOT gate using NAND
 AND gate using NAND
 OR gate using NAND
 NOR gate using NAND
 XOR gate using NAND
 XNOR gate using NAND

5. INTERNSHIP: AN OVERVIEW
 I want to express my gratitude mainly to my supervisor
Om Krishna Gupta Sir and Jitender Chhabra Sir ,
Department of Electronics and Communication
Engineering,AKGEC, who helped me from the very
beginning of my internship on ‘ANALOG AND DIGITAL
SYSTEM DESIGNING’.
 In this journey, I learnt a lot of things which includes
Study of semiconductors, Diodes ,Types of Analog and
Digital Circuits etc. Overall it was a great experience.

6. CLIPPERS
AND
CLAMPERS

7. Clippers
 Clipping circuit: A wave shaping circuit which controls the shape of
the output waveform by removing or clipping a portion of the applied
wave.
 Half wave rectifier is the simplest example. (It clips negative half
cycle).
 Also referred as voltage limiters/ amplitude selectors/ slicers.
 Applications:
- In radio receivers for communication circuits.
- In radars, digital computers and other electronic systems.
- Generation for different waveforms such as trapezoidal, or square
waves.
- Helps in processing the picture signals in television transmitters.
- In television receivers for separating the synchronizing signals from
composite picture signals

8. Types of clippers
 According to non- linear devices used:
- Diode clippers and Transistor clippers
 According to biasing
- Biased clippers and Unbiased clippers.
 According to level of clipping
- Positive clippers, Negative clippers and combination
clippers

9. THUMB RULE
Action of biasing on diode
 When diode is forward biased, it acts as a closed switch
( ON state).
 When diode is reverse biased, it acts as a open switch (
OFF state).

10. Diode Clippers

10
The diode in a series clipper “clips”
any voltage that does not forward
bias it:
•A reverse-biasing polarity
•A forward-biasing polarity less than
0.7 V (for a silicon diode)

11. Series Diode Configurations
Series clippers are again classified which are as follows:
 Series Negative Clipper
 Series Positive Clipper
 Biased Series Clipper

12. Series Negative Clipper
12
 The below figure shows a series negative clipper with its
output waveforms.
 During the positive half cycle the diode appears in the forward
biased and conducts such that the entire positive half cycle of
input appears across the resistor connected in parallel as
output waveform.
 During the negative half cycle the diode is in reverse biased.
No output appears across the resistor. Thus, it clips the
negative half cycle of the input waveform, and therefore, it is
called as a series negative clipper.

13. Series Positive Clipper
13
 The series positive clipper circuit is connected as shown in the
figure.
 During the positive half cycle, diode becomes reverse biased,
and no output is generated across the resistor.
 During the negative half cycle, the diode conducts and the
entire input appears as output across the resistor.

14. Parallel Clippers
14
The diode in a parallel clipper
circuit “clips” any voltage that
forward bias it.
DC biasing can be added in
series with the diode to change
the clipping level.

15. Parallel Diode Configurations
Parallel clippers are again classified which are as follows:
 Parallel Negative Clipper
 Parallel Positive Clipper
 Biased Parallel Clipper

16. Parallel(Shunt) Negative Clipper
16
 Shunt negative clipper is connected as shown in the below
figure.
 During the positive half cycle, the entire input is the output.
 During the negative half cycle, the diode conducts causing no
output to be generated from the input.

17. Parallel(Shunt) Positive Clipper
17
 During the positive half cycle the diode is in conduction mode
and no output is generated
 During the negative half cycle; entire input appears as output
as the diode is in reverse bias as shown in the above figure..

18. Biased Clippers
18
Adding a DC source in
series with the clipping
diode changes the
effective forward bias of
the diode.

19. Biased Series Clipper
19
 Series negative clipper with positive reference voltage is
similar to the series negative clipper, but in this a positive
reference voltage is added in series with the resistor.
 During the positive half cycle, the diode start conducting only
after its anode voltage value exceeds the cathode voltage
value.
 Since cathode voltage becomes equal to the reference
voltage, the output that appears across the resistor will be as
shown in the below figure.

20. Biased Parallel(Shunt) Clipper
20
 During the positive half cycle the diode conducts causing the
positive reference voltage appear as output voltage.
 During the negative half cycle, the entire input is generated as
the output as the diode is in reverse biased.

21. Combined Clipper Circuit:
21
 In addition to the positive and negative clippers, there is a
combined clipper which is used for clipping both the positive
and negative half cycles.
 The circuit is connected with a reference voltage, diodes D1 &
D2.
 During the positive half cycle, the diode the diode D1
conducts causing the reference voltage connected in series
with D1 to appear across the output.
 During the negative cycle, the diode D2 conducts causing the
negative reference voltage connected across the D2 appear
as output.

22. Zener Clipper Circuit:
22
 One easy way of creating biased diode clipping circuits
without the need for an additional emf supply is to use Zener
Diodes.
 The output waveform from full wave zener diode clipping
circuits resembles that of the previous voltage biased diode
clipping circuit. The output waveform will be clipped at the
zener voltage plus the 0.7V forward volt drop of the other
diode

23. Summary of Clipper Circuits
23

24. Summary of Clipper Circuits
24
more…

25. Drawbacks
 Series Diode Clipper
When diode is “OFF”, there should be no
transmission of input signal to output. But in
case of high frequency, signal transmission
occurs through diode capacitance which is
undesirable.
 Shunt Diode clippers
When diode is “OFF”, transmission of input
signal to output should take place. But in case of
high frequency input signals, diode capacitance
affects the circuit operation and signal gets
attenuated.

26. Clampers
26
A diode and capacitor can be
combined to “clamp” an AC signal
to a specific DC level.

27. Note:
 Start the analysis of clamping network, by considering that
part of the input signal that will forward bias the diode.
 During the period that the diode is in the “ON” state,
assume that capacitor will charge up instantaneously to a
voltage level determined by the network.
 Assume that during the period when the diode is in “OFF”
state, capacitor will hold on its established voltage level.
 Keep in mind the general rule, that
Total swing of total output = Swing of input signal

28. Positive Clamper:
28
 It is almost similar to the negative clamper circuit, but the
diode is connected in the opposite direction.
 During the positive half cycle, the voltage across the output
terminals becomes equal to the sum of the input voltage and
capacitor voltage (considering the capacitor as initially fully
charged).
 During the negative half cycle of the input, the diode starts
conducting and charges the capacitor rapidly to its peak input
value. Thus the waveforms are clamped towards the positive
direction.

29. Negative Clamper:
29
 During the positive half cycle, the input diode is in forward
bias- and as the diode conducts-capacitor gets charged (up to
peak value of input supply).
 During the negative half cycle, reverse does not conduct and
the output voltage become equal to the sum of the input
voltage and the voltage stored across the capacitor.

30. Biased Clamper Circuits
30
The input signal can be any type
of waveform such as sine, square,
and triangle waves.
The DC source lets you adjust
the DC clamping level.

31. Biased Negative Clamper:
31
 It is similar to the negative clamper, but the output waveform
is shifted towards the positive direction by a positive reference
voltage.
 As the positive reference voltage is connected in series with
the diode, during the positive half cycle, even though the
diode conducts, the output voltage becomes equal to the
reference voltage; hence, the output is clamped towards the
positive direction.

32. Biased Positive Clamper:
32
 A positive reference voltage is added in series with the diode
of the positive clamper as shown in the circuit. During the
positive half cycle of the input, the diode conducts as initially
the supply voltage is less than the anode positive reference
voltage.
 If once the cathode voltage is greater than anode voltage
then the diode stops conduction. During the negative half
cycle, the diode conducts and charges the capacitor. The
output is generated as shown in the figure.

33. Summary of Clamper Circuits
33

34. Practical Applications
 Rectifier Circuits
 Conversions of AC to DC for DC operated circuits
 Battery Charging Circuits
 Simple Diode Circuits
 Protective Circuits against
 Overcurrent
 Polarity Reversal
 Currents caused by an inductive kick in a relay circuit
 Zener Circuits
 Overvoltage Protection
 Setting Reference Voltages
34

35. Applications of Clippers
and Clampers
 Clippers find several applications, such as
• They are frequently used for the separation of synchronizing signals
from the composite picture signals.
• The excessive noise spikes above a certain level can be limited or
clipped in FM transmitters by using the series clippers.
• For the generation of new waveforms or shaping the existing
waveform, clippers are used.
• The typical application of diode clipper is for the protection of
transistor from transients, as a freewheeling diode connected in
parallel across the inductive load.
• Frequently used half wave rectifier in power supply kits is a typical
example of a clipper. It clips either positive or negative half wave of
the input.
• Clippers can be used as voltage limiters and amplitude selectors.

36.  Clampers can be used in applications
• The complex transmitter and receiver circuitry of television clamper is
used as a base line stabilizer to define sections of the luminance signals to
preset levels.
• Clampers are also called as direct current restorers as they clamp the
wave forms to a fixed DC potential.
• These are frequently used in test equipment, sonar and radar systems.
• For the protection of the amplifiers from large errant signals clampers are
used.
• Clampers can be used for removing the distortions
• For improving the overdrive recovery time clampers are used.
• Clampers can be used as voltage doublers or voltage multipliers.

37. NAND REALIZATION
OF CIRCUITS(Logic
Gates)

38. NAND GATE : A UNIVERSAL
KILLER
The standard 2-, 3-, 4- and 8-input NAND gates are
available:
 CMOS
 4011: Quad 2-input NAND gate
 4023: Triple 3-input NAND gate
 4012: Dual 4-input NAND gate
 4068: Mono 8-input NAND gate
 TTL
 7400: Quad 2-input NAND gate
 7430: Mono 8-input NAND gate
 7410: Triple 3-input NAND gate
 7420: Dual 4-input NAND gate
In digital electronics, a NAND gate (NOT-AND) is a logic gate which produces an output
which is false only if all its inputs are true; thus its output is complement to that of an
AND gate. A LOW (0) output results only if all the inputs to the gate are HIGH (1); if
any input is LOW (0), a HIGH (1) output results. A NAND gate is made using transistors
and junction diodes.

39. REALIZING NOT GATE FROM
NAND:
A Y=A’
0 1
1 0
Y=(A.A)’
= A’

40. REALIZING AND GATE FROM
NAND:
A B Y=A.B
0 0 0
0 1 0
1 0 0
1 1 1
Y=(A.B)’
=((A.B)’)’
=A.B

41. REALIZING OR GATE FROM
NAND:
A B Y=A+B
0 0 0
0 1 1
1 0 1
1 1 1
Y=A+B
=((A+B)’)’
=(A’.B’)’

42. REALIZING NOR GATE FROM
NAND:
A B Y=(A+B)’
0 0 1
0 1 0
1 0 0
1 1 0
Y=(A+B)’
=(A+B)
=((A+B)’)’
=(A’.B’)’

43. REALIZING XOR GATE FROM
NAND:
Y=A⊕B
=AB’+A’B
=A.(A’+B’) + B.(A’+B’)
=(A.(A.B)’)+ (B.(A.B)’)
=((A.(A.B)’)’+(B.(A.B)’)’)’
A B Y=A XOR B
0 0 0
0 1 1
1 0 1
1 1 0

44. REALIZING XNOR GATE FROM
NAND:
Y=AB+A’B’
=(A’B+AB’)’
=A.(A’+B’) + B.(A’+B’)
=(A.(A.B)’)+ (B.(A.B)’)
=((A.(A.B)’)’+(B.(A.B)’)’)’
A B Y=A XNOR B
0 0 1
0 1 0
1 0 0
1 1 1

45. BIBLIOGRAPHY
 www.google.com
 www.wikipedia.org
 www.electroboom.com
 Youtube-Last Moment Tutions, Neso
Academy,Electroboom…