Hi,
In the figure, what will happen if the gates of M3,M4 transistors are only connected to each other and aren't connected to any bias circuits?please explain
thanks.
If gate of M3 is connected to drain of M4 and other way round, then M3 M4 form a negative resistance, which may be difficult to control. Though this configuration is seldom used, when controlled or for very low output swings, it can greatly enhance the DC gain of the amp.