Need help, E-MOSFETS

Thread Starter

JohnM1

Joined May 7, 2015
8
Can't work this one out, can anyone help? **Please note part (a) isn't really a question, blame my electrotechnology lecturer for that.. **
 

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dl324

Joined Mar 30, 2015
16,845
If this is homework, you need to post in that forum. Otherwise some well intentioned person will help you cheat.

Besides, the question is ambiguous. What polarity are the MOSFETs? Hope that wasn't supposed to be a trick question...
 

Thread Starter

JohnM1

Joined May 7, 2015
8
Thanks for the reply, only new to this site, hadn't realised. It's an old exam question from a couple of years go, but I can only assume it's an N-Channel MOSFET, just because this was the only type we looked at, but thanks anyway, glad it's not only me who finds this slightly ambiguous
 

Thread Starter

JohnM1

Joined May 7, 2015
8
I have attempted the questions, think I made a correct diagram, not entirely sure though, and as for part (b) I really just don't know where to start, and unfortunately, there's not solution anywhere to try work backwards from
 

Thread Starter

JohnM1

Joined May 7, 2015
8
Yeah, here's the diagram I drew anyway, not sure if it's correct or not, best I could come up with without finding any similar examples.. Not entirely sure if the 10V should be where it is or connected to the drains
 

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Thread Starter

JohnM1

Joined May 7, 2015
8
As for math workings, I really don't know where to start I'm afraid, even a push in the right direction would be appreciated
 

Jony130

Joined Feb 17, 2009
5,487
If I understand description correctly, your diagram is incorrect.
Is the upper transistor gate connected to drain ?
Are you sure that this is a series connection ?
 

dl324

Joined Mar 30, 2015
16,845
I'd interpret having an upper and lower device as being in series, which is a common configuration.

What isn't clear is how many inputs there are.

If you don't know the answer and are unclear about the question, what is the point of answering them?
 

Thread Starter

JohnM1

Joined May 7, 2015
8
If I understand description correctly, your diagram is incorrect.
Is the upper transistor gate connected to drain ?
Are you sure that this is a series connection ?
I think I get what you mean about the upper transistor being connected to drain, thought it was connected in series.. Does this not mean that the source from one goes to the gate of the next? Can't find any examples of MOSFETS connected in series ( or at least as far as I can tell, could be completely misunderstanding it, probably am to be honest)
 

Thread Starter

JohnM1

Joined May 7, 2015
8
I'd interpret having an upper and lower device as being in series, which is a common configuration.

What isn't clear is how many inputs there are.

If you don't know the answer and are unclear about the question, what is the point of answering them?
Purely just because it came up in the past exam papers twice in a row. But yeah, think I'll give up on this one and pray it doesn't come up a third time, thanks for the help anyway
 

Jony130

Joined Feb 17, 2009
5,487
What isn't clear is how many inputs there are.
Unclear ?? How can it be?
The input to the circuit is taken to be the gate off the lower transistor
What is unclear in this sentence?

I think I get what you mean about the upper transistor being connected to drain, thought it was connected in series.. Does this not mean that the source from one goes to the gate of the next? Can't find any examples of MOSFETS connected in series ( or at least as far as I can tell, could be completely misunderstanding it, probably am to be honest)
Try Google "cs amplifier with active load"
 

Thread Starter

JohnM1

Joined May 7, 2015
8
Unclear ?? How can it be?

What is unclear in this sentence?


Try Google "cs amplifier with active load"
Will do, thanks

EDIT: just searched that, actually helps a lot, with the diagram and general understanding at least, I'll have another try at the maths again soon, thanks
 
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