You can apply a test voltage source between the nodes you want to determine the impedance. Then, set an equation which relates the resulting test current due to the applied test voltage. The ratio of the test voltage and test current is the impedance by Ohm's law.
You can also check these videos where I apply the method to determine the impedance: Transient Response Electric Circuits: ru-vid.com/group/PLuUNUe8EVqlk-KSGs6d50H_BuLydNzmAS
I need to get Rout in order to Calculate Av using Gm.Rout method so it's like take all the circuit and turn it to just a resistor. I understand the idea of applying a test voltage and measure the current while set input voltage to zero. The question is how to set that equation which relates V & I in your example ?@@CanBijles
@@Fidel-tk5rq The answer to question 'how', is best shown using an example. You can also check these videos where I apply the method to determine the impedance: Transient Response Electric Circuits: ru-vid.com/group/PLuUNUe8EVqlk-KSGs6d50H_BuLydNzmAS