共模反馈相关的管子应该如何工作

踟蹰的天

如上图所示，管子M3，M4应该工作在什么区？放大器的输出Ve的值应该是多少（换句话说负责共模反馈的放大器的输出的直流电压是多少？）M3，M4的尺寸又应该如何取？
感谢大家

任性

M3 ,M4 depend on your opamp operation current

踟蹰的天

   

任性 发表于 2022-2-27 03:29
M3 ,M4 depend on your opamp operation current

So the operation region of M3 and M4 doesn't matter as long as the amplifier works?

任性

   

踟蹰的天 发表于 2022-2-27 16:10
So the operation region of M3 and M4 doesn't matter as long as the amplifier works?

it matters, usually in the saturation region.

踟蹰的天

   

任性 发表于 2022-3-2 23:27
it matters, usually in the saturation region.

Thanks for answering questions.
But what about in subthreshold region if current is small enough? Is it proper when transistors works in subthreshold region?

任性

   

踟蹰的天 发表于 2022-3-3 12:28
Thanks for answering questions.
But what about in subthreshold region if current is small enough?  ...

If it fits your requirements, of course