# Question about MOSFET CS amplifier simulation

This is the project statement:

I have designed the circuit and it worked well. This is the circuit:

It contains 3 voltmeters and 1 ammeter as shown.

This is a plot for vin = vG, vout = vD, vS and iDS:

The question is: When I increase vin from +/- 100 mV to +/- 1 V, the plot becomes like this:

1- Why does vout become almost straight line when vin reaches its maximum values?

2- Why does vout become a straight line when `vin reaches its minimum values?

My guesses:

1- Because the MOSFET exits from the saturation region to the triode region.

2- Because the MOSFET becomes off.

I know my guesses -if they're correct- are brief and not enough (especially 1), so please provide me with detailed explanation about the reasons of the two cases