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LTC2499 datasheet recommended buffer seems like an odd choice

Category: Datasheet/Specs

https://www.analog.com/media/en/technical-documentation/data-sheets/2499fe.pdf says "The LTC6078 is an excellent amplifier for this function." in regards to an external buffer.

My understanding is the autocallibration will remove Vos and drift.

Looking at the LTC6078 datasheet I saw this graph of Vos vs Vcm:

(https://www.analog.com/media/en/technical-documentation/data-sheets/60789fa.pdf)

For a single-ended sensor am I reading this correctly in concluding that I should expect up to +/-  40uV (~7 bits?) of nonlinearity from poor CMRR and that this will not be removed by the autocallibration?

If that is the case, is either an OPA141 or OPA196 a reasonable choice? Any other recommendations for a particularly suitable buffer for this ADC? (This is to avoid impedance mismatch in reading a  single-ended sensor with a variable impedance from ~200k to 200R).

Thanks

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