Hey all,
I have a question on the source follower circuit - I was reading the text Analog Electronics by Behzad Razavi. I have this doubt with the source follower circuit. I would like to know whether the Vout thats taken from the source is actually Vout . Because, while taking the derivative of large signal analysis, I found that the term dVsb / dVin is taken to be dVout / dVin.

Also, I dont know if this is the right away to post questions here.
really appreciate the help.

Thanks,
Anjali

 

Do you really think we should know what circuit you are talking about and where Vin, Vout and Vsb are in the circuit?

 

S.c.h.e.m.a.t.i.c - with a unique reference designator for each component.

Paraphrasing Rear Admiral Joshua Painter,

"Engineers don't take a dump, son, without a schematic."

ak

 

when asking for help, good idea is to formulate the problem as if it is an exam question. you need to post everything necessary to analyze problem. if you state it in a way that is as concise as possible but makes further discussion unnecessary, you have succeeded.

 

Welcome to AAC! The question posed in post #1 is a very good way to ask a question. In fact, much better than many of the questions posed.
So the answer is, that in a source follower circuit, the voltage taken from the source is CERTAINLY Vout!
I will not vouch for the other explanations, nor evaluate the other terms, but the voltage between the source and the supply common is certainly Vout.

 

Hey all,
I have a question on the source follower circuit - I was reading the text Analog Electronics by Behzad Razavi. I have this doubt with the source follower circuit. I would like to know whether the Vout thats taken from the source is actually Vout . Because, while taking the derivative of large signal analysis, I found that the term dVsb / dVin is taken to be dVout / dVin.

Also, I dont know if this is the right away to post questions here.
really appreciate the help.

Thanks,
Anjali

If Vout is the signal taken at a point named Fred, then that is actually Vout because that is the signal that is defined as Vout.

You need to be more explicit with your description -- a schematic would REALLY help.

What is Vsb? The source-body voltage?

If so, what is the body tied to? Again, a schematic would REALLY help.

Why does dVsb/dVin being equal to dVout/dVin imply that Vout is not actually Vout (assuming you explain what it means for Vout to not actually be Vout in the first place).

Don't make us read your mind. Show a schematic and explain your reasoning.