A basic current mirror is shown below:
The load and reference current relationship is affected by channel length modulation:
In order to cancel the effects of channel length modulation, vds1 and vds2 need to be equal. A cascode current mirror is needed to make this happen, but how? The book I'm using is by Razavi..
Vn = Vgs3 + Vds2
Then, in order to make Vds1=Vds2, vn must satisfy:
Vn = Vgs3 + Vds1 or Vn = Vgs3 + Vgs1
But from the circuit:
Vn=Vgs0 + Vgs1 !!!
How are Vgs0 and Vgs3 equal?