36.6.2.15 Reference Buffer Compensation Offset

A hardware compensation using a reference buffer can be used. When the REFCTRL.REFCOMP bit is set, the offset of the reference buffer is sensed during the ADC sampling phase. This offset will be then canceled during the conversion phase. This feature allows for the decrease of the overall gain error of the ADC.

There is a digital gain correction (refer to Offset and Gain Correction) but contrary to that digital gain correction, the hardware compensation will not introduce any latency. However, when using REFCOMP and if the ADC reference selection is not using VDDANA (REFCTRL.REFSEL != INTVCC2), the first 5 conversions of the ADC must be discarded after the ADC is enabled.