super source follower 是怎么反馈的

redwall76

Figure 2 shows a modified architecture of source follower knownas Super Source Follower [3, 4]. A common source amplifier is connected across the common drain stage. Whencurrent through M1 increases, the gate voltage of M2 also increases which in turn reduces Vout since M2 is in commonsource configuration. When Vout is reduced, the voltage difference between gate and source of M1 decreases thereby reducing the the current though M1. This confirms the negative feedback action.

为什么M1的电流增大了，M2的栅极电压就会增大呢？为什么就会使Vout下降呢？

xuwenwei

上拉的电流变大了自然会把该节点的电压往上拉啊，M2的栅极电压就会上升，M2的栅极上升了，下拉的电流变大了 自然就把Vout拉低了啊

战神盖瑞

因为M4的Gate是固定偏置，M1电流增大必然M4的Drain增大，所以Vout就减小了

李玉彬

redwall76

战神盖瑞 发表于 2022-3-6 10:54
因为M4的Gate是固定偏置，M1电流增大必然M4的Drain增大，所以Vout就减小了

但是为什么M2的栅极电压增大了就会使VOUT减小呢？

redwall76

11111

hxy328126243

如果VOUT降低，VSGM1降低，IDSM1减小，又因为IDSM3=IDSM1+IOUT(IDSM2),所以IOUT（IDSM2）增加，VGM2增加。