This article deals with a simple differentiator circuit, using an operational amplifier.
If we use the generic formula of the transfer function of a generic operational inverting amplifier, we can write:
G(s)=-\frac{Z_f}{Z_i}=
=-\frac{R}{\frac{1}{sC}}=RCs
Where Z_f is the feedback impedance, while Z_i is the impedance connected to the input.
The transfer function has just one zero in the origin and, for that reason , it behaves like a differentiator. If we compare the final expression with the Bode form of the transfer function,
K\cdot\frac{(1+T_1s)\cdot...(1+\frac{2\zeta_1s}{\rho_{n1}}+\frac{s^2}{\rho_{n1}^2})\cdot...}{s^n\cdot(1+\tau_1s)\cdot...(1+\frac{2\xi_1s}{\omega_{n1}}+\frac{s^2}{\omega_{n1}^2})\cdot...}
it’s easy to see that there are just two meaningful parameters: K and n.
| Parameter | Value |
| K | RC |
| n | -1 |