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How Source and Drain are interchangeable?

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doubtsforknowledge

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Can anyone explain me how source and drainare intrchangeable ??
How can we prove that source and drain are interchangeable??
 

flatulent

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Re: Source and Drain

It all depends upon the construction. On some it is horizontal and symmetrical and so they are. On some they are double diffused which makes them not symmetrical.

It also depends upon which end is also connected to the substrate.

I would not assume that any discrete FET is symmetrical.
 

MSRA

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Re: Source and Drain

Well as far as i know...
the basic structire of mosfet(nmos) has two n type and one p type substrate...and if you cut the mosfet from the mid then the two sides are symmetrical both in terms of shape and properties...so thats how drain and source are interchangable
 

cai2

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Re: Source and Drain

it depends upon what type of jfet transistor. Try to see or find the datasheet of the transistor. There you can find its structure and location where does the drain and source are located....:D
 

ubna

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Re: Source and Drain

In a jfet due to symmetry of the structure, the gate looks and works exactly alike when viewed from drain and source...
 

A.Anand Srinivasan

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Re: Source and Drain

i wouldn't assume all of them to be interchangeable because some come with a internal connection to one of the side(source) but if it comes with four terminals it maybe interchangeable.... but even then there is doping to consider which would change the parameters of the device considerably....
 

rat_race

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Re: Source and Drain

u can find your answer at gray meyer's book , chapter 4. good luck
 

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