Cliping & Clamping Of diodes

8/13/2019 Cliping & Clamping Of diodes

http://slidepdf.com/reader/full/cliping-clamping-of-diodes 1/19

1

Application of diodes

• Rectifier circuits

• Clipper circuits

• Clamper circuits



2

Rectifier circuits

Circuits that convert an ac signal into a

dc signal

Two types: Half-wave rectifier & Full-wave rectifier



3

Half-wave rectifier



4

Half-wave rectifier



5

Full-wave rectifier



6

Full-wave rectifier







9

Clipper Circuit

• Clipper circuits have the ability to ‘clip’

off a portion of the input signal withoutdistorting the remaining part of thealternating waveform.





Clamper Circuit



12

Clamper Circuit

• The clamping network ‘clamp’ a signal to different dclevel without altering the wave-shape.

• The network will have a capacitor, a diode and a resistiveelement.

• The magnitude of R and C must be chosen such that thetime constant t = RC is large enough to ensure that thevoltage across the capacitor does not dischargesignificantly during the interval the diode is non-conducting

• Used in TV receivers as a DC restorer



Diode :- ClamperPositive Clamper

The circuit for a positiveclamper is shown in thefigure. During the negativehalf cycle of the input signal,the diode conducts and actslike a short circuit. The output

voltage Vo 0 volts . Thecapacitor is charged to thepeak value of input voltageV m

. and it behaves like abattery. During the positive

half of the input signal, thediode does not conduct and

acts as an open circuit. Hencethe output voltage Vo Vm+ Vm This gives a positively

clamped voltage.

Vo Vm+ Vm = 2 Vm



Diode :- ClamperPositive Clamper



Diode :- Clamper

Negative Clamper

During the positive halfcycle the diode conductsand acts like a short circuit.The capacitor charges topeak value of input voltageV m. During this interval theoutput Vo which is taken

across the short circuit willbe zero During the negativehalf cycle, the diode is open.The output voltage can be

found by applying KVL.



Diode :- Clamper

Negative Clamper



Diode :- ClamperBiased Clamper



Diode :- Clamper

The circuit of a positively biased clamper is shown in the figure. During the negativehalf cycle of the input signal the diode isforward biased and acts like a short

circuit. The capacitor charges to Vi + Vs .Applying the KVL to the input side

During the positive half cycle of the input signal, thediode is reverse biased and it acts as an open circuit.Hence V

s has no effect on V

o. Applying KVL around

the outside loop.



LP3 19

•In the positive half cycle C

gets charged through D to10V (peak of sine wave + 5

V) with the straight plate of

C at a higher potential. D

Clips the output to amaximum of -5V.

•In the negative half cycle

D is reverse biased. The

output can reach a

minimum of –15V (-VC +

negative peak of sine

wave).

How Does A Clamp Circuit Work?

Documents

Cliping & Clamping Of diodes