Digital correlation technique for the estimation and correction of DAC errors in multibit mash ΔΣ ADCs

A fully digital algorithm is described for acquiring and correcting the errors of the feedback DAC used in a multibit ΔΣ MASH ADC. The method operates in the background and is highly accurate. It is particularly useful for wideband ADCs, where mismatch error shaping becomes ineffective. Combined with an improved digital adaptive compensation technique, which greatly reduces the raw quantization leakage in MASH architecture, it makes the design of fast and accurate ADCs using inaccurate components possible.