An NMOS transistor with kn=4 mA/V2 and Vt=.5 V is operated with Vos=1 V. At what value of VDS does the transistor enter the saturation region? What value of ID is obtained in saturation? Solution NMOS will enter saturation when, Vds = Vgs -Vt = 1 - 0.5 = 0.5V Id = Kn * (Vgs-Vt)2 in saturation = 4 * (0.5)2 = 1mA so Id = 1mA.

1. An NMOS transistor with kn=4 mA/V2 and Vt=.5 V is operated with Vos=1 V. At what value of
VDS does the transistor enter the saturation region? What value of ID is obtained in saturation?
Solution
NMOS will enter saturation when, Vds = Vgs -Vt = 1 - 0.5 = 0.5V
Id = Kn * (Vgs-Vt)2 in saturation
= 4 * (0.5)2 = 1mA
so Id = 1mA