ron and rout in DC analysis

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anhnha

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In cadence DC analysis operating point there are two parameters ron and rout.
I see that ron and rout are defined for all operating region (sub-threshold, triode, saturation).
So, what are the definition or how these parameters are calculated in these regions?
It makes sense to define ron in triode region but I don't quite understand how should I understand ron in other regions.
 

anhnha said:
... It makes sense to define ron in triode region but I don't quite understand how should I understand ron in other regions.
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It's the same in saturation region: ron = δVds/δIds . Gives you a good feeling for the Early voltage, respectively for the output impedance e.g. of a current source|mirror.

BTW: subthreshold is not a region, but an operation mode.
 
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    anhnha

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Thanks for the answer!
So, for example, in saturation what is the difference between Ron and Rout here?
 

anhnha said:
... for example, in saturation what is the difference between Ron and Rout here?
Click to expand...

Not only in saturation, in any region: Ron = 1/gds of the transistor alone, whereas Rout includes the resistance (in parallel) of all possible other devices in parallel, e.g. more parallel drivers, mostly only the load.
 

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