All,
I have noticed the non-linearity issue that is discussed in errata ADC27 (SLAZ054C–July 2009–Revised July 2010).
The fix for this is to output the internal reference voltage. I have demonstrated that this fixes my non-linearity problem.
However, now I measure an internal reference of 2.1VDC instead of 2.5VDC. The only external VeREF+ load I have is a .1uF ceramic cap connected to VeREF- (which is connected to analog ground).
As confirmation, my digitized ADC output is scaled to a full-scale voltage of 2.1V, whereas it was 2.5V before the errata fix.
Can anyone explain this and how to resolve it?
Thank you