Binary tree structure random Dynamic Element Matching technique in current-steering DACs

A novel Dynamic Element Matching (DEM) method is presented to improve the static and dynamic performance of Nyquist-rate current-steering digital to analog converter (DAC). Compared to conventional DEM methods, this approach only increases or decreases the number of selected unit current sources randomly when the input code changes. Thus, signal dependent distortions can be eliminated efficiently at high sampling frequencies. A 6-bit current-steering DAC model adopting the proposed DEM coding method was built up to verify the performance in MATLAB. It could reach a better SFDR (56dB) value and a better DNL (0.26LSB) and INL (0.45LSB) value compared with traditional DEM methods.