Slew rate is defined as the maximum rate of change of the op amp output voltage per unit of time in the closed-loop configuration under large-signal condition. Slew rate indicates how rapidly the op amp output can change in response to change in the input frequency. It is given as
The Slew rate of an op-amp is fixed. If the slew rate isthen it means that the op-amp output voltage can change maximum by 10 V in 1 .
The ideal value of the slew rate is infinite. Practically it is a finite value and it is due to the following reasons
- saturation of internal stages and
- the finite time constant of internal capacitors
Consider figure 1. Vi and Vo are respectively the input and output of the op amp. Av is the closed-loop voltage gain.
Therefore, the output voltage
For producing undistorted op amp output,must be less than the slew rate i.e.