A digital background correction technique combined with DWA for DAC mismatch errors in multibit ΣΔ ADCs

A digital background correction technique combined with data weighted averaging (DWA) algorithm is presented to overcome the digital-to-analog converters (DACs) unit element mismatch errors in multibit sigma-delta modulators (ΣΔMs). This technique needs a background measurement process. The circuit-level simulation results confirm the validity of the measurement process and the system-level simulation results are provided to verify the usefulness of this correction technique in low oversampling ratios (OSRs). This method enhances the peak signal-to-noise and distortion ratio (SNDR) about 11.5 dB with respect to the DWA algorithm when the OSR is 8.