Hi aman,
Quote:by looking intuitively if we see that as iF increases then gate of MF increases. Now MF is in common source config , so drain of MF should decrease i think . Wat do you say ??
or even if we assume Vout to be constant initially then increase in iF will also cause decrease in drain voltage in common source.
If the load of the MF is a resistor/transistor, the drain voltage of MF decreases as its gate voltage increases because it sinks more current. In that case, the relationship of gate voltage and drain voltage depends on the I/V curve of both the common source amplifier and its load, eg. an resistor load.
But if Iin increases, the drain voltage increases if the gate voltage is not changing, I mean assuming there is not feedback. And the drain voltage increases a lot because that is a high impedance node. Now the negative feedback makes the gate voltage of MF increases so that the drain voltage would not increases so much.
Best Regards,
Yawei