Or - Lower gain at higher frequencies.

 

Or - Lower gain at higher frequencies.

Yes - that´s true. However, is this the aim of the capacitor?
Does this help to explain why we are using the cap?
Rather, I think this is the (unwanted) consequence of loop gain enhancement (phase enhancement).

 

It`s really interesting to see how many different approaches are possible to explain the effect of this additional capacitor (frequency domain, time domain, loop gain, opamp´s gain roll-off, compensated voltage divider,..).
And all these explantions come to the same conclusion:
Improvement of stability.

Probably has something to do with differences in education approach. My explanation was a simple version of the way I learned it, and I've realized that my courses have been less theoretical and more practical than similar things I find online from other schools/sources.

 

Inverting or Non Inverting Op amps amplifier using Rin Resistor , Rf feedback resistor

At high frequencies the feedback capacitor's impedance is low, ESR is low, so it passes the high frequency but the Op amps gain is LOWER because the capacitor impedance and Rf feedback resistor is in parallel so the Gain is lower at higher frequencies?

The Caps Impedance at high frequencies is in parallel with the Rf feedback resistor which makes the Op amps gain lower?

Didn't say you were wrong LvW, just that stability was not the question.

 

Didn't say you were wrong LvW, just that stability was not the question.

OK - agreed.
However, I was of the opinion that it could be helpful - also for other beginners reading this thread - to tell the whole story (because gain and stability are closely related).