Another important frequency related parameter of an op-amp is the slew rate. (Slew rate is the maximum rate of change of output voltage with respect to time. Specified in V/μs).

**Slew Rate:**

Another
important frequency related parameter of an op-amp is the slew rate. (Slew rate
is the maximum rate of change of output voltage with respect to time. Specified
in V/μs).

**Reason for Slew rate:**

There is
usually a capacitor within 0, outside an op-amp oscillation. It is this
capacitor which prevents the o/p voltage from fast changing input. The rate at
which the volt across the capacitor increases is given by

dV_{c}/dt
= I/C --------(1)

I ->
Maximum amount furnished by the op-amp to capacitor C. Op-amp should have the
either a higher current or small compensating capacitors.

For 741
IC, the maximum internal capacitor charging current is limited to about 15μA.
So the slew rate of 741 IC is

SR = dV_{c}/dt
|_{max} = Imax/C .

For a sine wave input, the effect of slew rate
can be calculated as consider volt follower -> The input is large amp, high
frequency sine wave .

If V_{s}
= V_{m}Sinwt then output V_{0} = V_{m}sinwt . The rate
of change of output is given

dV_{0}/dt
= V_{m} w coswt.

The max
rate of change of output across when coswt =1

(i.e) SR
= dV_{0}/dt |max = wV_{m}.

SR = 2∏fV_{m}

V/s =
2∏fV_{m} v/ms.

Thus the
maximum frequency f_{max} at which we can obtain an undistorted output
volt of peak value V_{m} is given by

f_{max}
(Hz) = Slew rate/6.28 * V_{m} .

called
the full power response. It is maximum frequency of a large amplitude sine wave
with which op-amp can have without distortion.

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Linear Integrated Ciruits : Characteristics of op-amp : Slew Rate |

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