I am using the QB4 ADC with a 5k potentiometer across the supply and its tap to ADP0. The response is not as linear as I had hoped (see attached file).
I have tried different clocks, clock rates, number of bits (10 or 12) fast or low power setting, and all results are practically identical to the one shown. Is this as good as I can expect from this arrangement? I can linearise the response using a look-up table, but would the response vary from device to device?