为什么MOS管的栅极可以输入电流

HeshamAhmed

It's a positive feedback from x to vout you have a -ve gain through M1 and from vout to x you have another -ve gain through M2 so -ve x -ve = +ve
the way he explains it is, you have a capacitor at node x, if Iin increase so the current inside the cap at x increase then Vx increases and vout decreases reducing the current in M2 (ID2), so the current drawn from the cap at x (ID2) decreases and Vx goes up more then it's a positive feedback