Clipper CircuitsLET’S REMOVE UNWANTED PART OF SIGNALS

1Electronic Devices and

Circuits (2131006)

Index

1. What are clipper circuits?

2. Types of clipper circuits.

3. Unbiased positive clipper.

4. Unbiased negative clipper.

5. Biased series positive clipper.

6. Biased series negative clipper.

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What are clipper circuits?

Clippers Circuits are used to remove the part of a signal that is

above or below some defined reference level.

One of the simple example of a clipper is the half-wave rectifier –that circuit basically cut off everything at the reference level of zero

and let only the positive-going (or negative-going) portion of the

input waveform through.

Clipping circuits (also known as limiters, amplitude selectors, or

slicers)

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Types of Clippers Circuits

Unbiased Clipper Circuit

Unbiased Positive clipper

Unbiased Negative

clipper

Biased clipper circuit

Biased positive clipper

Biased negative clipper

Clipper circuits

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Note:

In all the explanations we have

considered the diode to be ideal.

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Unbiased positive Clippers

Positive clippers are used to clip positive portions of the input signal

and allow the negative portions of the signal to pass through

Figure below shows the input and output signal along with the positive clipper. The positive cycle is completely clipped off by the

clipper.

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Continued…

Section (b) shows the same clipper configuration as it is shown in (a), but

the diode is replaced with its equivalent circuit model. When the input

signal goes positive, the cathode terminal of diode attains a higher

potential than anode. This makes the diode reverse biased. The diode in

reverse biased configuration can be modelled as an open switch. This is

indicated in the figure. As the diode acts as an open switch, no current

flows through the load and hence no output appears across the load. This is

the reason why the positive cycle is completely clipped off.

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Unbiased Negative clippers

Negative clippers are used to clip Negative portions of the input

signal and allow the positive portions of the signal to pass through

Figure shows the input and output signal along with the negative clipper. The negative cycle is completely clipped off by the clipper.

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Continued…

Section (b) shows the same clipper configuration as it is shown in (a), but

the diode is replaced with its equivalent circuit model. When the input

signal goes positive, the anode terminal of diode attains a higher potential

than cathode. This makes the diode forward biased. The diode in reverse

biased configuration can be modelled as an open switch. This is indicated

in the figure. As the diode acts as an closed switch, no current flows through

the load and hence no output appears across the load. This is the reason

why the negative cycle is completely clipped off.

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Biased series positive clipper

As shown earlier, we saw that the clipping of the signal takes place

as soon as the input signal goes positive. If we want to

change/adjust the clipping level of AC voltage, then external biasing voltage must be used. The figure given below shows a

biased (series) clipper.

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Working11

Biased Series negative Clipper

As shown earlier, we saw that the clipping of the signal takes place

as soon as the input signal goes negative. If we want to

change/adjust the clipping level of AC voltage, then external biasing voltage must be used. The figure given below shows a

biased (series) clipper.

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Working13

Thank You

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