A crictical op-amp question!

[spbhu]

I am still not sure about this simple question:
When a 2 stage op-amp is connected in voltage follower configuration, when an input signal is applied, how will the internal node voltage of the opamp change? E.g. the drain of the input transistor? It seems it cannot be changed too much, because of the high gain, if the voltage change (e.g. by ±0.1V), then a 50v/v gain will make the output signal change by ±5V, which is not correct if Vdd is 3V.
So how do we determine the signal change at these internal nodes?
Thanks very much.

 

[safwatonline]

feedback signal makes the real input to the diffrential pair really small (in uV )

 

[kivvzhou]

Because the output signal is following the input signal,so the differential input signal is very samll!

 

[isaacnewton]

feedback signal makes the real input to the diffrential pair really small (in uV )

That's right. You need to consider the negative feedback.