Thus, the circuit behaves like a voltage follower. The non-inverting input terminal of the op-amp is connected to ground through a resistor R comp, which provides the input bias compensation, and the inverting input terminal is connected to the output through the feedback resistor R f.
Ideal Op-Amp Differentiator CircuitĪn op-amp differentiating amplifier uses a capacitor in series with the input voltage source, as shown in the figure below.įor DC input, the input capacitor C 1, after reaching its potential, cannot accept any charge and behaves like an open-circuit. In other words, the circuit behaves like a high-pass filter. Differentiating circuits are usually designed to respond for triangular and rectangular input waveforms.ĭifferentiators have frequency limitations while operating on sine wave inputs the circuit attenuates all low frequency signal components and allows only high frequency components at the output. Active differentiators have higher output voltage and much lower output resistance than simple RC differentiators.Īn op-amp differentiator is an inverting amplifier, which uses a capacitor in series with the input voltage. Similarly, if the input signal is a sinusoid, then the output signal is also a sinusoid but with phase difference of 90 0.Ī differentiator with only RC network is called a passive differentiator, whereas a differentiator with active circuit components like transistors and operational amplifiers is called an active differentiator.
For example, if the input signal is a ramp, then the output of the circuit with an Operational Amplifier as Differentiator will be simple DC (as the rate of change of ramp signal is constant). Mathematically speaking, the output signal of a Differentiator is the first order derivative of the input signal. It produces an output signal where the instantaneous amplitude is proportional to the rate of change of the applied input voltage.