Imput impedance

Thread Starter


Joined Jun 24, 2015
Hello,I have a very basic question ¿What's the imput impedance on this circuit?

I'm not sure if it is Zin=Vsignal/i or Zin=Va/i ?
Last edited:


Joined Mar 31, 2012
I'm sorry I don't speak English I'm just trying...
Don't worry -- you're English is far better then my (fill-in-your-native-tongue-here).

now I understand your point it is Zin=Vsignal/i, because Vsignal is the input
Correct. Vsignal is the input voltage and i is the input current. The ratio between them is therefore the input impedance.

Though there are really two input impedances -- large signal and small signal; but I don't know if you have gotten to that yet.