preethi19
Full Member level 5
Hi i have attached an image of the 3 BJT configuration.
Could anyone pls tell me intuitively without and equation why the respective configurations have the their corresponding input and output impedance.
1) For CB ---> My understanding is input is IE and impedance is nothing but resisting flow of IE. So Since E-B are forward biased there exists not much resistance in IE flow. Output IC has high output impedance is becoz as C-B are reverse biased with increase of VBC the depletion region increases causing increased resistance is IC flow resulting in very high output impedance. (I am trying to learn so sorry if i'm wrong abt this. Pls correct if wrong!!!)
2) For CE----> For CE i found some related explanation in one site. It B-E is forward biased so there generally wont be much resistance to IB. But Resistance to IB occurs due to the +ve terminal given to collector which repels away the holes in the Base causing medium input impedance.
But CE and CC have very similar configuration except for the resistor RL. So is that the reason which partially causes change in input and output impedance of CE and CC configuration??? Is my understanding on the resistor RL part right??? Pls help.. Thanks in advance!!!
Could anyone pls tell me intuitively without and equation why the respective configurations have the their corresponding input and output impedance.
1) For CB ---> My understanding is input is IE and impedance is nothing but resisting flow of IE. So Since E-B are forward biased there exists not much resistance in IE flow. Output IC has high output impedance is becoz as C-B are reverse biased with increase of VBC the depletion region increases causing increased resistance is IC flow resulting in very high output impedance. (I am trying to learn so sorry if i'm wrong abt this. Pls correct if wrong!!!)
2) For CE----> For CE i found some related explanation in one site. It B-E is forward biased so there generally wont be much resistance to IB. But Resistance to IB occurs due to the +ve terminal given to collector which repels away the holes in the Base causing medium input impedance.
But CE and CC have very similar configuration except for the resistor RL. So is that the reason which partially causes change in input and output impedance of CE and CC configuration??? Is my understanding on the resistor RL part right??? Pls help.. Thanks in advance!!!