A dynamic element matching technique for reduced-distortion multibit quantization in delta-sigma ADCs

A dynamic element matching (DEM) technique to mitigate the distortion caused by comparator offsets in the flash ADC of a ΔΣ modulator is presented. Measurement results for a high-performance ΔΣ modulator IC using comparator offset DEM are shown to demonstrate the significant reduction in offset-related spurious tones the technique provides. Analysis and simulation of comparator offset DEM in a flash ADC with a periodic input and uniform dither are presented to give insight into its operation and to quantify the spur attenuation it provides