34.10.4.2 Performance with the Hardware Offset and Gain Correction

Inherent gain and offset errors affect the absolute accuracy of the ADC. The offset error cancellation is handled by the Offset Correction register (OFFSETCORR) and the gain error cancellation, by the Gain Correction register (GAINCORR). The offset and gain correction value is subtracted from the converted data before writing the Result register (RESULT).

Table 34-23. Offset and Gain correction features
Gain Factor Conditions Offset Error (mV) Gain Error (mV) Total Unadjusted Error (LSB)
0.5x In differential mode, 1x gain,
VDDANA = 3.0V, VREF = 2.0V, 350 ksps
T = 25°C 0.25 1.0 2.4
1x 0.20 0.10 1.5
2x 0.15 -0.15 2.7
8x -0.05 0.05 3.2
16x 0.10 -0.05 6.1