Hi.
I hope you can clarify 2 doubts I came across when I read this sentence in 6th edition SEDRA and SMITH's book "Microelectronic circuits", in page 359: "From this model we observe that if transistor is used as a two-port network with the input between E and B and the output port between C and B, then the current gain observed is equal to alfa." (see the model image attached, please)
1) Why don't they consider the INPUT being between C and B and the OUTPUT being E and B? This is confusing me..
2) Is correct to tell that: the current I(c) is drawn as if it was there a current-source controlled by the emissor current?? i.e. bigger I(e) leaves to bigger I(c)?
3) Just more one addendum for now: I have read in some electronic websites and some books and it is constantly referring the "large-signal models" and "small-signal models" on transistors. Is it correct to tell that the former is referred to the DC signals? And for small-signal models it is usually (always?) referred to AC signals that we want amplify in the transistor? Mine idea is: if we want to amplify a small AC signal, we first must biasing the signal with a DC component so we can use the linear region and in this way the small AC signal will not saturate.. (i.e. having clips in their peaks..). Is it correct? Please feel free to fix any errors. Thank you.
Thanks in advance for your attention and patience!
ps This is not my native language. Sorry for any mistakes...
I hope you can clarify 2 doubts I came across when I read this sentence in 6th edition SEDRA and SMITH's book "Microelectronic circuits", in page 359: "From this model we observe that if transistor is used as a two-port network with the input between E and B and the output port between C and B, then the current gain observed is equal to alfa." (see the model image attached, please)
1) Why don't they consider the INPUT being between C and B and the OUTPUT being E and B? This is confusing me..
2) Is correct to tell that: the current I(c) is drawn as if it was there a current-source controlled by the emissor current?? i.e. bigger I(e) leaves to bigger I(c)?
3) Just more one addendum for now: I have read in some electronic websites and some books and it is constantly referring the "large-signal models" and "small-signal models" on transistors. Is it correct to tell that the former is referred to the DC signals? And for small-signal models it is usually (always?) referred to AC signals that we want amplify in the transistor? Mine idea is: if we want to amplify a small AC signal, we first must biasing the signal with a DC component so we can use the linear region and in this way the small AC signal will not saturate.. (i.e. having clips in their peaks..). Is it correct? Please feel free to fix any errors. Thank you.
Thanks in advance for your attention and patience!
ps This is not my native language. Sorry for any mistakes...
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