Common Collector Amplifier

Here is new one topic of BJT that is Common Collector Configuration circuit. In this circuit collector terminal of BJT is common for input and output loop.

INPUT Loop:

Input loop of CC is base collector where we apply the Vin as shown in circuit diagram.

OUTPUT Loop: 

where as the output loop of the this circuit is emitter collector as shown on diagram. and we get Vout as VEC.

when Vin increase then conduction of BJT increase and max current flow through Collector to emitter and high current will appear at output. 

When Vin go down then conduction of BJT decrease and we get reverse current at output loop, means CC has high current gain but Voltage gain approximately unity.

have some following Properties:

Properties:

Av ------- Unity

Ai -------- High

Zi --------- High

Zo --------- low

Application:

use for Impedance matching

use for Current amplification