CLAMPING CLAMPING CIRCUITES,CLIPPERCIRCUITES,CLIPPER

&&PEAK DETECTORSPEAK DETECTORS

CLAMPING CLAMPING CIRCUITES,CLIPPERCIRCUITES,CLIPPER

&&PEAK DETECTORSPEAK DETECTORS

Dr. C. Saritha, Lecturer in Electronics

S.S.B.N P.G COLLEGE, ANANTAPUR

OVERVIEW

INTRODUCTIONDEFINATIONS CIRCUIT DIAGRAMS WAVEFORMS CONCLUSION

• Some of the non linear function circuits are :

CLAMPERS CLIPPERS PEAK DETECTORS

INTRODUCTION

CLAMPING CIRCUITS The clamping circuits in general, designed

“clamp” the top or bottom of a waveform.

Fixed d.c. level, which may be zero, while preserving its shape and amplitude

The distinguishing feature of a clamper is that is it adjusts the d.c. level without needing to know the exact waveform.

• Zero volts-waveforms

CLAMPING CIRCUITS:

Waveforms :

Operation of the circuit : input voltage vi = vm sin ω t and vref

Interval 0 ≤ ω t ≤ π :

Vi is positive, Vd is negative V0 is negative the diode is reverse biased. No current flows through the capacitor i.e. it is not charged.

Interval π ≤ ω t ≤ 3 π/2 : Vi is negative V0 is positive. The diode conducts and the NV terminal of the op amp behaves as virtual ground. The capacitor c1 gets charged with point A at a potential higher than that of point be the capacitor gets charged to the peak value Vm of the input voltage.

Interval ω t > 3π/2 :Vd = - (Vm + Vi) = -Vm (1+sin ωt )

And diode D is OFF. As a result the output voltage. V0 = - Vd = Vm (1+sin ωt )

Reference voltage the capacitor gets charged to (Vm +vref ) the output voltage.

V0 = Vm sin ωt + (Vm +vref )

Examples : Vm = 10 v and Vref = 5v

V0 = 10 sin ωt +10+5 = 10 sin ωt + 15

Waveforms for +vref and –vref :

CLIPPER Clipper are circuits which can

clipp off a portion of the input waveform without distorting the rest of the waveform.

Clipping circuits are also refer limiter amplitude selectors or slicers.

POSITIVE CLIPPER :

Precession diode which can be used to slice off a portion of the positive half of the input signal. The level at which clipping is done is determined by the reference voltage.

Positive clipper :

Positive clipper waveforms :

NEGATIVE CLIPPER :

Reversed and the reference voltage the resulting circuit is a negative clipper circuit. it clips OFF the negative region of the input signal waveform below the reference voltage.

Negative clipper circuit :

Negative clipper waveforms :

PEAK DETECTORS

Detector : The maximum value is called detector

Peak detectors : Peak detectors ate electronic circuits that track the input signal faithfully until it detects a peak and holds that value until a new, Larger peak is detected.

Basic peak detector :

The diode allows un directional current to charge the capacitor. The capacitor stories the charge and acts as a voltage memory. It holds the peak value of the input voltage. To detect a peak, S1 has to be closed and S2 open. To hold the peak value both the switches should be open. To reset the circuit, S1 has to be opened and S2 closed.

Basic peak detector :

Peak detector waveform :

Thank you