16 February 2018

Compare Voltage Amplifier and Power Amplifier

Voltage amplifier
  • The function of the voltage amplifier is to raise the voltage level of the input signal. 
  • The input resistance of the transistor is low whereas the output resistance of the transistor is very high. 
  • The collector resistance should be comparatively high. 
  • The transistor is employed with thin base, therefore the value of current amplification factor β is high. 
  • The first stage of the multistage amplifier should be voltage amplifier.i.e.RC coupling. Less distortion in the output signal.
Power amplifier
  • The function of the power amplifier to raise the power level of the input signal.
  • The base of the transistor is made thicker in order to handle large current. 
  • The size of the power amplifier is made sufficiently larger in order to dissipate heat. 
  • As the base is handle large current, the value of current amplification factor β is small ( IC = β IB
  • The last stage of the multistage amplifier should be power amplifier. 
  • Large distortion in the output signal.
You may also like :