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Design >> Mixed-Signal Design >> INL - integral non-linearity. what is the real definition? [DACs]
https://designers-guide.org/forum/YaBB.pl?num=1236008394

Message started by mowiehowie on Mar 2^nd, 2009, 7:39am

Title: INL - integral non-linearity. what is the real definition? [DACs]
Post by mowiehowie on Mar 2^nd, 2009, 7:39am

Hello everyone, I've got a simple question.

I am studying about DACs, actually I am working at one. So every book I get brings the same definition about INL, - "the difference between the actual output value and a straight line between the first and last point, or the best-fit line (this one is rarely used at the books), after gain and offset errors have been removed"

but on practical examples, they always just make the difference between the ideal values and actual values outputs, after removing offset and gain errors. i can't see how it fits the definitions above.

could anyone please give me a light?

Title: Re: INL - integral non-linearity. what is the real definition? [DACs]
Post by mowiehowie on Mar 2^nd, 2009, 7:46am

ok, its like.. after removing the gain error and the offset error the first and last points will be very close to the ideal output points, so the line between the first and the last point is the ideal line... but why is that true only for the first and last points, i mean.. i can see in my little experience with this dac is that after removing gain and offset errors the first and last point gets very close to the ideal (like 0.002 LSB difference), but its not true for every point... its not making sense to me.

Title: Re: INL - integral non-linearity. what is the real definition? [DACs]
Post by mowiehowie on Mar 2^nd, 2009, 7:48am

i guess it all comes down to the definition of gain and offset that are used.

Title: Re: INL - integral non-linearity. what is the real definition? [DACs]
Post by ywguo on Mar 4^th, 2009, 7:50pm

mowiehowie,

The defintion is true. What is you said "one practical example"?

Quote:

but on practical examples, they always just make the difference between the ideal values and actual values outputs, after removing offset and gain errors. i can't see how it fits the definitions above.

Yawei