Differential pair active load contradiction
My answer (March 1, 2021) to SE EE question Differential pair active load contradiction And another time I said that Razavi's book is not the place where you can find an intuitive explanation. So even now, seeing the unconvincing explanations for this famous circuit solution... and then the specific detailed explanations in the following answers, I could not stop explaining the idea in ashort answer. There he is... My answer "Active load" is an abstract circuit concept but it can be explained in a simple intuitive way by more elementary electrical concepts as voltage divider, potentiometer, variable resistor, etc... So, M2 and M4 can be considered as two variable "resistors" R2 and R4 in series forming a variable "voltage divider"... or a sensitive "potentiometer" - Fig. 1. It is controlled in a differential manner so that when R2 increases, R4 decreases and vice versa (the resistance crossfades). As a result, the total resistance R2 + R4 s...