I was looking at a certain circuit in which there was the necessity of generating 3 DC current sources (10uA, 50uA, 250uA), starting from a given current source of 10uA. Let's consider firstly the circuit which has to generate 10uA (let's call it A).
1st question: can you explain me how does it works, in an intuitive way? Why is the current I4 copied to the transistor M10 (i.e. M10 is a current mirror 1:1)?
Now let's consider the circuits which have to generate 50uA and 100uA (let's call them B and C):
They are connected to I4 through the label VBN, as for circuit A. So B is a current mirror 1:5, C is a current mirror 1: 25. This result is reached by inserting 5 transistors in the first one (molteplicity = 5 so there are 5 transistors in series) and 25 transistors in the second one (molteplicity = 25).
2nd question: can you explain me intuitively why the number of transistors is equal to the multiplication factor of the current?