Hi,
Usually MOS amplifier are always analysed with respect to its input and output impedance. But I am unable to relate this with the understanding of the MOS amplifiers.
LIke. Whether i/p impedance or o/p impedance should be low or high..
How the impedance will affect the performance of the amplifier?
A Mosfet has an extremely high input impedance. But almost no source needs an amplifier with such a high input impedance.
I think a ph sensor needs an amplifier with an extremely high input impedance. I have never seen them.
Some loads like a loudspeaker should be driven by an amplifier with an extremely low output impedance to damp their resonances. Any half-decent transistor or Mosfet amplifier has an extremely low output impedance.