An Area-Optimized Digitally-Assisted DAC Employing a Matrix-Based DEM Scheme

The Dynamic Element Matching (DEM) technique’s role is to mitigate mismatch issues in complex, matrix-based systems. Previous work employing a matrix-based random DEM scheme demonstrated enhanced linearity and spectral characteristics in the Digital to Analog Converter’s (DAC) thermometric decoded section. This paper presents the design of an area-optimized, DEM-assisted 9-bit segmented DAC. The optimal segmentation level for area-performance is initially established. Subsequently, to mitigate area constraints from the integral nonlinearity (INL) requirement and improve spectral performance, we utilize the matrix-based DEM engine from prior research. The proposed 9-bit DAC, implemented in a commercial 180 nm CMOS process, achieves a total harmonic distortion (THD) of -79 dB and a spurious-free dynamic range (SFDR) of 79 dB, resulting in 8× and 16× improvements in SFDR and THD, respectively, over its non-DEM counterpart.