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Anonymous Poster

Operational Amplifers

10/03/2010 5:24 AM

for an open circut under operational amplifiers why is it that the gain(A) is only between the ranges of 10^5 and 10^7
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user-deleted-1105
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#1

Re: Operational amplifers

10/03/2010 6:58 AM

It's the difference between the ideal and the practical and real world. You can rarely use the full gain anyway unless you want the output to be digital and sit at one rail or the other, in which case you may wasnt to add positive feedback. For most applictions negative feedback is used to provide stability and a controlled gain/frequency response.
How much gain do you need? What are you amplifying?
If it's more than that you will doubtless need several stages to acheive any sort of stability.
It's better to have 3 stages with a gain of 10 than one stage with a gain of 1000.
If this is just a purely theoretic question. The answer is it doesn't matter a jot and to ponder it is pretty much a waste of time unless you are actually designing an op amp, in which case you wouldn't be asking the Q.
Del

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TonyS
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#2
In reply to #1

Re: Operational amplifers

10/03/2010 7:14 AM

A bit grumpy this morning Del? Did Middleburgh get to you yesterday?

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user-deleted-1105
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#3
In reply to #2

Re: Operational amplifers

10/03/2010 7:32 AM

Blimey, no, to come back from 2-0 down and gett a point was great.
I'm just fed up with random Qs which appear to have no practical use, if they are just for theoretical interest I feel the questioner should be wasting his time not mine. No prizes for guessing the thread I have in mind.
Any how I think my answer is a finely crafted work of great merit in fact one might say it was "good"
Del

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TonyS
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#4
In reply to #3

Re: Operational amplifers

10/03/2010 8:11 AM

Being bribed by a cat what is the world coming to!

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