16/11/2020

Common Emitter Transistor Amplifier

 

  • The common emitter transistor amplifier is shown in the figure A. 
  • The input signal is applied between base and emitter whereas the output is taken from collector and emitter. 
  • The output voltage equation VCE is given by

        VCE = VCC – icRC

  • As the input voltage increases in the positive half cycle, the base current increases. 
  • As IC = βIB, the collector current also increases due to base current increases. 
  • As the collector current increases, the collector to emitter voltage decreases because supply voltage VCC remains constant.

       VCE = VCC – icRC

  • As the signal voltage increases in the positive direction, the output voltage increases in the negative direction. 
  • It means that the output signal is 180 degree phase difference with input signal.
Mathematical Formula

    VCE = VCC – icRC

Differential above equation

    dVCE = 0 – dicRC

    dVCE = – dicRC

  • The negative sign indicates that the output voltage is 180 degree out of phase with respect to input voltage.

Phase Reversal

  • There is 180 degree phase reversal in the common emitter between input signal and output signal is known as phase reversal.
  • The input positive signal increases in the positive direction, the output signal increases in the negative direction and vice versa in the common emitter transistor amplifier connection. 
  • Therefore we can say that there is 180 degree phase difference between input signal and output signal.

You may also like :

What is function of Hollow Conductor?

Disadvantages of Low Power Factor

How tempering is done in the Energy Meter?

Important Earthing Rules As Per IE Rules – 1956 

No comments:

Post a comment