3. INTRODUCTION
• Some of the non linear function
circuits are :
CLAMPERS
CLIPPERS
PEAK DETECTORS
4. 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.
8. 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.
9. 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 )
10. Examples :
Vm = 10 v and Vref = 5v
V0 = 10 sin ωt +10+5
= 10 sin ωt + 15
12. 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.
13. 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.
16. 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.
19. 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.
20. 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.