Clipper (Limiting) Circuit Experiment

Virtual Labs
IIT Kharagpur

Clipper (Limiting) Circuits

Introduction

Clipper (Limiting) Circuits:
Clipping circuits are used to select for transmission that part of an arbitrary waveform which lies above or below some reference level. Clipping circuits are also refered as voltage (or current) limiters, amplitude selectors or slicers

Objective

To study the behaviour of clipping (limiting) circuits for following cases.

Clipper circuit with diode in series

Case 1: Clipper circuit with forward biased diode in series
Case 2: Clipper circuit with reverse biased diode in series

Clipper circuit with diode in shunt

Case 3: Clipper circuit with forward biased diode in shunt
Case 4: Clipper circuit with reverse biased diode in shunt

Clipping at two different levels

Case 5: Clipper Circuit with limiting at two different levels

Theory

Clipper circuit with diode in series

The clipper circuit with diode in series has two cases such as diode connected in forward bias and in reverse bias.

Case 1: Clipper circuit with forward biased diode in series

The clipper circuit has a forward biased diode D in series with a reference voltage in shunt as shown in figure below.

Clipper circuit with forward biased diode in series

If input voltage \( v_i > V_r \) then the diode D is in forward bias means "ON" state. The output voltage \( v_o=v_i \).
The transfer curve has one break at \( v_o=v_i=V_{r}\) and has the following characteristics (assuming \( V_{r}>>V_{\gamma}\) and \( R_f << R \)).

Input (\(v_i\))	Output (\(v_o\))	Diode state
\( v_i > V_{r} \)	\( v_o=v_i \)	D ON
\( v_i \leq V_{r} \)	\( v_o = V_{r} \)	D OFF

The input signal \(v_i\) is shown below
Input waveform

The output signal \(v_o\) is shown below
Output waveform

The input-output signal together \(v_i / v_o\) is shown below
Input/Output waveform

Case 2: Clipper circuit with reverse biased diode in series
The clipper circuit has a forward biased diode D in series with a reference voltage in shunt as shown in figure below.

If input voltage \( v_i < V_r \) then the diode D is in forward bias means "ON" state. The output voltage \( v_o=V_i \).
The transfer curve has one break at \( v_o=v_i=V_{r}\) and has the following characteristics (assuming \( V_{r}>>V_{\gamma}\) and \( R_f << R \)).

Input (\(v_i\))	Output (\(v_o\))	Diode state
\( v_i < V_{r} \)	\( v_o=v_i \)	D ON
\( v_i \geq V_{r} \)	\( v_o = V_{r} \)	D OFF

The input signal together \(v_i\) is shown
Input waveform

The output signal together \(v_o\) is shown
Output waveform

The input-output signal together \(v_i / v_o\) is shown
Input/Output waveform

Clipper circuit with diode in shunt

The clipper circuit with diode in shunt has two possible cases such as diode connected in forward bias and in reverse bias.
Case 3: Clipper circuit with forward biased diode in shunt

Clipper circuit with forward biased diode in shunt

If input voltage \( v_i < V_r \) then the diode D is in forward bias means "ON" state. The output voltage \( v_o=v_i \).
The transfer curve has one break at \( v_o=v_i=V_{r}\) and has the following characteristics (assuming \( V_{r}>>V_{\gamma}\) and \( R_f << R \)).

Input (\(v_i\))	Output (\(v_o\))	Diode state
\( v_i < V_{r} \)	\( v_o=v_i \)	D OFF
\( v_i \geq V_{r} \)	\( v_o = V_{r} \)	D ON

The input signal together \(v_i\) is shown
Input waveform

The output signal together \(v_o\) is shown
Output waveform

The input-output signal together \(v_i / v_o\) is shown
Input/Output waveform

Case 4: Clipper circuit with reverse biased diode in shunt
The clipper circuit with reverse biased diode in shunt is in belwo figure.

Input (\(v_i\))	Output (\(v_o\))	Diode state
\( v_i > V_{r} \)	\( v_o=v_i \)	D OFF
\( v_i \leq V_{r} \)	\( v_o = V_{r} \)	D ON

The input signal together \(v_i\) is shown
Input waveform

The output signal together \(v_o\) is shown
Output waveform

The input-output signal together \(v_i / v_o\) is shown
Input/Output waveform

Clipping at two different levels

Case 5: Clipper Circuit with limiting at two different levels
Diodes may be used in pairs to perform double-ended limiting at independent levels. A parallel, series or a series-parallel arrangement can be used. A parallel arrangement is shown in circuit below.

The transfer curve has two break points, one at \( v_o=v_i=V_{r1}\) and a second one at \( v_o=v_i=V_{r2}\), and has the following characteristics (assuming \( V_{r2}>V_{r1}>>V_{\gamma}\) and \( R_f << R \)).

Input (\(v_i\))	Output (\(v_o\))	Diode states
\( v_i \leq V_{r1} \)	\( v_o=V_{r1} \)	D1 ON	D2 OFF
\( V_{r1}< v_i < V_{r2} \)	\( v_o=v_i \)	D1 OFF	D2 OFF
\( v_i \geq V_{r2} \)	\( v_o=V_{r2} \)	D1 OFF	D2 ON

The input signal together \(v_i\) is shown
Input waveform

The output signal together \(v_o\) is shown
Output waveform

The input-output signal together \(v_i / v_o\) is shown
Input/Output waveform

Simulation

Instructions

Observe the circuit diagram of the Clipper.
Click on the Power Button .
Select the Amplitide(A) of the input sine wave signal(V_i).
Select the frequency of the signal(f) for the input signal(V_i).
Select the battery voltage(V_r)
Observe the input signal(V_i) and clipped output signal(V_o) in the graph.
Change the values of A, f and V_r to observe the variation in the output signal.
Hover on the graph to observe the value of the V_i and V₀ at that instatnt of time T.
Save the graph if you are done with your experiment.
Note:

Make sure always V_r<=A

Instructions

Select the Amplitide(A) of the input sine wave signal(V_i).
Select the frequency (f) of the signal for the input signal(V_i).
Select the battery voltages V_r2 and V_r2 such that, V_r2 > V_r1.
Observe the input signal(V_i) and clipped output signal(V_o) in the graph.
Change the values of A, f and V_r1 and V_r2 to observe the variation in the output signal.
Hover on the graph to observe the value of the V_i and V_o at that instatnt of time T.
Save the graph if you are done with your experiment.
Note:

Make sure always V_r1 <= A and V_r2 > V_r1.

To change the values just scroll by hovering on it.

Power

Circuit OFF

Function Generator Controls

V_i = V

f = kHz

Battery Voltage Control

V_r = V

Battery Voltage Controls

V_r1 = V

V_r2 = V

Oscilloscope Controls

Channel 1

V_c1 = V/div

Time = (ms)/div

Position

P_X =

P_Y =

Channel 2

V_c2 = V/div

Time = (ms)/div

Position

P_X =

P_Y =

References

Books

M. Halkias. Integrated Electronics. McGraw-Hill electrical and electronic engineering series. Tata McGraw-Hill Publishing Company, 2001.

NPTEL Lectures

Link 1

Link 2

Clipper (Limiting) Circuits

Introduction

Objective

Theory

Clipper circuit with diode in series

Clipper circuit with diode in shunt

Clipping at two different levels

Pre-Quiz

Simulation

Select an option from below list

Power

Function Generator Controls

V_i = V

f = kHz

Battery Voltage Control

V_r = V

Battery Voltage Controls

V_r1 = V

V_r2 = V

Oscilloscope Controls

Channel 1

V_c1 = V/div

Time = (ms)/div

Position

P_X =

P_Y =

Channel 2

V_c2 = V/div

Time = (ms)/div

Position

P_X =

P_Y =

Post-Quiz

References

Books

NPTEL Lectures

Feedback

Introduction

Objective

Theory

Clipper circuit with diode in series

Clipper circuit with diode in shunt

Clipping at two different levels

Pre-Quiz

Simulation

Select an option from below list

Power

Function Generator Controls

Vi = V

f = kHz

Battery Voltage Control

Vr = V

Battery Voltage Controls

Vr1 = V

Vr2 = V

Oscilloscope Controls

Channel 1

Vc1 = V/div

Time = (ms)/div

Position

PX =

PY =

Channel 2

Vc2 = V/div

Time = (ms)/div

Position

PX =

PY =

Post-Quiz

References

Books

NPTEL Lectures

Feedback

V_i = V

V_r = V

V_r1 = V

V_r2 = V

V_c1 = V/div

P_X =

P_Y =

V_c2 = V/div

P_X =

P_Y =