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Reviewing Basic amplifier stage properties, I found unanimously that a Current Amplifier has a Very Low (ideally zero) Input Impedance and a Very High (ideally infinite) Output Impedance. The Emitter Follower's Input/Output impedances however show totally contrasting properties (High Input and Low Output impedance), and from small signal models its quite easy to see that the Emitter Follower does provide a significant current gain (β+1). Quite naturally I am not being able to comprehend these conflicting facts, from an intuitive viewpoint. Does it have to do with the fact that it is a voltage buffer? Please help.

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The Emitter Follower's Input/Output impedances however show totally contrasting properties (High Input and Low Output impedance), and from small signal models its quite easy to see that the Emitter Follower does provide a significant current gain (β+1)

You need to do a small-signal analysis of the input impedance for signals above the base-emitter diode voltage (~.6 volts). In this regime, you'll see that a small increase in voltage will produce a large current increase, which is the mark of a low impedance.

Likewise, if you hold the base current constant, you'll see that the emitter current does not vary much for variations in load resistance. And this is a mark of high output impedance. Granted, for a single transistor it's not outrageously good, since beta varies with current and collector-emitter voltage.

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An emitter-follower is not a (good) current amplifier, although its large/small signal models amplifies current. But the impedances of the emitter-follower disqualify it as a (good) current amplifier.

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