I am evaluating the ADuC848 for a data acquisition project.

I have bought the Accutron development kit and I am using Keil 'C' compiler (demo).

Using an accurate voltage calibrator as source, I am not able to get a linear response.

I am using the AD in the following mode :
Unipolar input
External reference (2.5V)
Single ended input (tried with differential as well)
16.5 samples/s
Chopper enabled
50/60Hz filter

Has anyone used this chip, or similar with Sigma-Delta, succesfully ?

Please help.

Thanks,

Diego