Slew rate of an op-amp

[FreshmanNewbie]

I read that the slew rate of an op-amp the rate at which the output voltage changes with time with respect to a step change in input.

So my question is will the slew rate of an op-amp depend on external circuit components?

Suppose,

1. I have a capacitor at the output of an op-amp. In this case, the slew rate will not be the same as mentioned in the op-amp datasheet correct?
(I think that adding a capacitor at the output of an op-amp is not a good idea as its purpose is not to charge a capacitor or moreover I haven't seen a requirement where there would be a capacitor requirement at the output of the op-amp. Please correct me if I am wrong).

2. What impact would a diode create on the slew rate of the op-amp if it is placed at the output?

3. On what external factors does the slew rate of an op-amp depend upon?

 

[danadakk]

Intrinsic slew rate of an OpAmp is governed by internal compensation C and
the current source biasing the stage. Actual response of course large Cload
will limit rate of change of output due to driver stage available current limita-
tions. Usually the limit is output stage current limiter in limit. Which is dominant
obviously based on Cload value.

Slew Rate is a large signal response issue, application notes discuss this.

Adding Cload generally not desired, decreases phase margin (stability) due to
OpAmp output Z causing phase lag with Cload, affecting feedback.

https://www.ti.com/lit/pdf/sloa332

https://www.ti.com/lit/an/snoa852/snoa852.pdf

Understanding Slew Rate in Op-Amp and How to Measure and Calculate it for your Designs

Understanding Slew Rate in Op-Amp and How to Measure and Calculate it for your Designs

components101.com

Your diode question, one could imagine in one direction it decoupling the
OpAmp from the Cload, like as in rectifier, so OpAmps output would slew
at its intrinsic rate in one direction, not the other. Cload when its decoupled, its
change dependent on load discharge path. Also depends on is diode in feedback
path or just a series connection from OpAmp output to Cload.


Regards, Dana.