I am calculating the gain of a common collector amplifier. It seems that Vout =Vin and the gain is always 1. Anything wrong?

 

Very close, at least for small low frequency AC signals.

The emitter has some resistance (dependent upon current and temperature), so if the emitter load is anything other than an ideal (infinite impedance) current source you will have some loss because of the drop across the emitter resistance.

 

Very close, at least for small low frequency AC signals.

The emitter has some resistance (dependent upon current and temperature), so if the emitter load is anything other than an ideal (infinite impedance) current source you will have some loss because of the drop across the emitter resistance.

Thank you!

 

I am calculating the gain of a common collector amplifier. It seems that Vout =Vin and the gain is always 1. Anything wrong?

Voltage gain, current gain or power gain? Yes, voltage gain is not the objective in that circuit.

 

That's why it's called an emitter follower circuit.
The emitter basically follows the base.