I want to ask about CS amplifier with active load.
Does this circuit always operate in triode region as long as Vin > Vth?
Here is my understanding:
1) Assume that the transistor is in saturation:
Id = 1/2*Kn* (Vgs - Vth)^2 = 1/2*Kn* (Vin - Vth)^2
If Vin increases => Id increases. This is impossible because Id = constant
2) Assume the transistor is in triode:
Id = 1/2* Kn * ((Vgs - Vth)*Vds - Vds^2) = 1/2* Kn * ((Vin - Vth)*Vds - Vds^2)
If Id = constant and Vin increase, then the only way to make the equation hold is Vds change.
=> In CS amplifier with active load the transistor always operate in triode region, right?
Does this circuit always operate in triode region as long as Vin > Vth?
Here is my understanding:
1) Assume that the transistor is in saturation:
Id = 1/2*Kn* (Vgs - Vth)^2 = 1/2*Kn* (Vin - Vth)^2
If Vin increases => Id increases. This is impossible because Id = constant
2) Assume the transistor is in triode:
Id = 1/2* Kn * ((Vgs - Vth)*Vds - Vds^2) = 1/2* Kn * ((Vin - Vth)*Vds - Vds^2)
If Id = constant and Vin increase, then the only way to make the equation hold is Vds change.
=> In CS amplifier with active load the transistor always operate in triode region, right?