17.4.13.1.1 Error Compensation Coefficient Calculation
To calculate the ADC gain error compensation coefficient, two reference voltages are required. The ADC has one selectable input connected to either 1/16 or 15/16 of the AVDD voltage. This selection can be made by setting the VREFSEL bit in the IBIASCON register. When it is assumed that the ADC offset after calibration using the 15/16*AVDD reference selection (IBIASCON.VREFSEL = 1) is zero, Equation 17-2 can be used to calculate the compensation coefficient.