Is there any easy way to determine the linearity of an op-amp from the datasheet? I'd like to build a test circuit to measure the linearity of some other components, so I'd like to know that an op-amp, configured as a unity gain buffer is not contributing more than .1ppm error over a limited output range. Measuring such errors is not trivial so can they be estimated? Datasheets rarely seem to mention linearity other than where THD is specified.
The large signal gain is obviously one of the most important factors as is CMRR. The latter can be avoided by operating with a 0V common mode voltage, but what other important factors apply? Presumably the more inherently linear the various stages of the amplifier are, the less the need for high gain?
Would an inverting or non-inverting arrangement be better from a linearity point of view?
I'm guessing that the output stage is the major contributor to non-linearity so how big an output swing could I use before linearity deteriorates significantly - I don't need more than 5V swing, but even +/- 1V would be useable? Would 80 or 90% of the minimum specified swing be reasonable? Would using amps with higher supply voltages help much?
Could anyone recommend suitable op-amps? Offset and drift are not really problems but low noise is important. It would be driven by a low impedance source so input resistance and bias currents would not be an issue.
What about audio amps such as the LME49990 which is advertised as 'ultra low distortion, ultra low noise'?
For AC signals (< 100Hz), the open loop gain roll-off will be a factor but presumably other frequency dependant non-linearity errors appear that aren't applicable at DC?
Sorry for the number of questions but any insights you can provide would be appreciated,
Splin