13-04-2013, 04:35 PM
OP AMP Applications – Integrator and Differentiator Circuits
AIM:
To design and verify the operation of an integrator and differentiator for a given input.
THEORY:
Integrator:
In an integrator circuit, the output voltage is integral of the input signal. The output
voltage of an integrator is given by Vo = -1/R1Cf Vidt
t
o
At low frequencies the gain
becomes infinite, so the capacitor is fully charged and behaves like an open circuit. The gain
of an integrator at low frequency can be limited by connecting a resistor in shunt with
capacitor.
Differentiator:
In the differentiator circuit the output voltage is the differentiation of the input
voltage. The output voltage of a differentiator is given by Vo = -RfC1
dt
dV i . The input
impedance of this circuit decreases with increase in frequency, thereby making the circuit
sensitive to high frequency noise. At high frequencies circuit may become unstable.
PROCEDURES:
Integrator
1. Connect the circuit as per the diagram shown in Fig. 8.4
2. Apply a square wave/sine input of 4V(p-p) at 1KHz
3. Observe the output at pin 6.
4. Draw input and output waveforms as shown in Fig. 8.6
Differentiator
1. Connect the circuit as per the diagram shown in Fig. 8.5
2. Apply a square wave/sine input of 4V(p-p) at 1KHz
3. Observe the output at pin 6
4. Draw the input and output waveforms as shown in Fig. 8.7