Operational Amplifier Applications Unit 2 – Integration and Differentiation
The integrating network is formed by the feedback capacitor (CF) and the input resistor (RIN).
For low frequencies and dc, CF can be ignored, and the circuit acts like a linear inverting
amplifier.
The output of a differentiator circuit is a voltage that is proportional to the change in slope of the
input waveform. The example shown is a ramp input waveform that differentiates into a square
wave output.
The rising portion of the input wave-form represents a constant slope. Since there is no change
in the slope, the corresponding portion of the differentiator output is a horizontal line.
When the input slope goes negative, the output transition is positive due to the inverting
amplifier configuration.
Conversely, when the input slope goes positive, the output transition is negative.
Increasing the differentiator's input frequency causes the output amplitude to increase.