In Neamen's microelectronic book, there's a problem using this current mirror
There is a 5V DC voltage source above the current source. The reference current is 250 microAmp. The threshold voltage is 1V. The transistors are matching (W/L is 3 for both). The Kn' is 80 microAmp/volts squared.
Also, Instead of ground, there's a -5V DC voltage.
What is the VGS of the two transistors?
from the figure, it seems that the Vgs should be 10V. Since assuming there's no voltage drop acroos the current source, V+ - V- = Vgs. However, getting the Vgs from the drain current equation
yields a 2.44V.
Which one is corrent and why?
EDIT: And no this is not a homework question.