Feedback Amplifier Topologies

Feedback Amplifier Topologies


Negative criticism in an enhancer is the strategy for sustaining a segment of the opened up yield to the information yet in the inverse stage. The stage restriction happens as the intensifier gives the 180o stage move through the criticism arrange doesn't. 

While the yield vitality is being connected to the contribution, for the voltage vitality to be taken as input, the yield is taken in shunt association and for the present vitality to be taken as criticism, the yield is taken in arrangement association. 

Two negative input circuits

  1. Negative Voltage Feedback 
  2. Negative Current Feedback 

Negative Voltage Feedback 

In this technique, the voltage criticism to the contribution of the enhancer is relative to the yield voltage. This is additionally grouped into two sorts − 
  1. Voltage-arrangement criticism 
  2. Voltage-shunt criticism 

Negative Current Feedback 

In this technique, the voltage criticism to the contribution of the intensifier is corresponding to the yield current. This is additionally arranged into two kinds. 

  1. Current-arrangement input 
  2. Current-shunt input 


Voltage-Series Feedback 

In the voltage arrangement criticism circuit, a small amount of the yield voltage is connected in an arrangement with the information voltage through the input circuit. This is otherwise called shunt-driven arrangement encouraged criticism, i.e., a parallel-arrangement circuit. 

The accompanying figure demonstrates the square graph of voltage arrangement criticism, by which it is clear that the criticism circuit is set in shunt with the yield yet in arrangement with the info.
Voltage-Series Feedback
As the criticism circuit is associated with shunt with the yield, the yield impedance is diminished and because of the arrangement associated with the info, the information impedance is expanded. 


Voltage-Shunt Feedback 

In the voltage shunt criticism circuit, a small amount of the yield voltage is connected in parallel with the info voltage through the input arrangement. This is otherwise called shunt-driven shunt-sustained input i.e., a parallel-parallel proto write. 

The beneath figure demonstrates the piece outline of voltage shunt criticism, by which it is apparent that the criticism circuit is set in shunt with the yield and furthermore with the info.


Voltage-Series Feedback

As the criticism circuit is associated with shunt with the yield and the contribution also, both the yield impedance and the info impedance are diminished. 


Current-Series Feedback 

In the present arrangement criticism circuit, a small amount of the yield voltage is connected in arrangement with the info voltage through the input circuit. This is otherwise called arrangement-driven arrangement nourished input i.e., an arrangement circuit. 

The accompanying figure demonstrates the square outline of current arrangement criticism, by which it is clear that the criticism circuit is set in arrangement with the yield and furthermore with the information. 
Voltage-Series Feedback

As the criticism circuit is associated in arrangement with the yield and the contribution also, both the yield impedance and the info impedance are expanded. 


Current-Shunt Feedback 

In the present shunt criticism circuit, a small amount of the yield voltage is connected in arrangement with the info voltage through the input circuit. This is otherwise called arrangement-driven shunt-nourished input i.e., an arrangement parallel circuit. 

The beneath figure demonstrates the square chart of current shunt criticism, by which it is clear that the criticism circuit is put in arrangement with the yield however in parallel with the info. 

As the criticism circuit is associated in arrangement with the yield, the yield impedance is expanded and because of the parallel association with the info, the information impedance is diminished. 

Voltage-Series Feedback


Give us now a chance to organize the enhancer qualities that get influenced by various sorts of negative criticisms.


CharacteristicsTypes of Feedback
Voltage-SeriesVoltage-ShuntCurrent-SeriesCurrent-Shunt
Voltage GainDecreasesDecreasesDecreasesDecreases
BandwidthIncreasesIncreasesIncreasesIncreases
Input resistanceIncreasesDecreasesIncreasesDecreases
Output resistanceDecreasesDecreasesIncreasesIncreases
Harmonic distortionDecreasesDecreasesDecreasesDecreases
NoiseDecreasesDecreasesDecreasesDecreases