Question on ADC - Electronic Circuits Projects Diagrams Free

aiva · 5th July 2006, 06:37 PM

I have an ADC with nonlinearity 0.0015% (AD7714) but want to get beter accuracy in measuring signal lower then 1/2 REF.

Whether the error of nonlinearity decreases at increase in factor of amplification of the entrance amplifier? Thanks

aiva · 5th July 2006, 07:49 PM

Quote:

Originally Posted by aiva

Whether the error of nonlinearity decreases at increase in factor of amplification of the entrance amplifier?

O, please, help me. I think yes, but i'm not sure
Or it is jast fullish quastion?

**Nigel Goodwin** · 5th July 2006, 08:02 PM

It's probably a foolish question! - and doesn't make much sense either?.

Oznog · 5th July 2006, 09:56 PM

Look at your device's spec sheet. There should be info on how reducing Vref will affect the linearity and offset.

If the spec sheet doesn't say, then it's hard to draw any generalizations. Perhaps you could contact tech support for the mfg. I've done this many times with good results.

6th July 2006, 01:38 AM

Amplify the input signal as the non-linearity is a function of the conversion, the bigger the input signal the less obvious the non-linearity.

aiva · 6th July 2006, 07:59 AM

Thanks all for the answer
Certainly it is necessary to contact the manufacturer. I should guess. Obviously it is the shortest way. Successes to you.

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5th July 2006, 06:37 PM	(permalink)
aiva	Question on ADC I have an ADC with nonlinearity 0.0015% (AD7714) but want to get beter accuracy in measuring signal lower then 1/2 REF. Whether the error of nonlinearity decreases at increase in factor of amplification of the entrance amplifier? Thanks

5th July 2006, 08:02 PM	(permalink)
Nigel Goodwin	It's probably a foolish question! - and doesn't make much sense either?. __________________ PIC programmer software, and PIC Tutorials at: http://www.winpicprog.co.uk

5th July 2006, 09:56 PM	(permalink)
Oznog	Look at your device's spec sheet. There should be info on how reducing Vref will affect the linearity and offset. If the spec sheet doesn't say, then it's hard to draw any generalizations. Perhaps you could contact tech support for the mfg. I've done this many times with good results. __________________ I thought what I'd do was I'd pretend I was one of those deaf-mutes.

6th July 2006, 01:38 AM	(permalink)
Paul Obrien	Amplify the input signal as the non-linearity is a function of the conversion, the bigger the input signal the less obvious the non-linearity.

6th July 2006, 07:59 AM	(permalink)
aiva	Thanks all for the answer Certainly it is necessary to contact the manufacturer. I should guess. Obviously it is the shortest way. Successes to you.