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[Moved]: flipped voltage follower details

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simplsoft

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can anyone help me in understanding what is the advantage of using flipped voltage follower instead of a normal source follower. I have read its output resistance is further reduced. How is it reduced? whats happen in flipped voltage follower that reducing output imepdance. What else is its advantage. I can understand its working

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t4_v

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Re: flipped voltage follower details

I cannot see the reduction in the output resistance. I have never met this circuit before, but for me there is a protection of Ib current source. In figure (a) Vo swing changes may affect Ib value (depends on the output impedance of the current source). In figure (b) Ib current source is "protected". Vo voltage swing has lower dependence on Ib value.

For sure disadvantage of figure (b) is the fact that Vo swing is reduced.
 

ZoOneR

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Re: flipped voltage follower details

Hi,
The output resistance of the flipped voltage follower is reduced due to negative feedback. If you apply a small signal model, you can deduce that the output resistance is 1/(gm1*gm2*ro2). The output resistance of the simple source follower is simple 1/gm1.
 
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ICdesignerbeginner

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Re: flipped voltage follower details

I have read in researvh articles that flipped voltage follower are used for low supply voltage. How can you explain please?
 

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