Impact of gradient error on switching sequence in high-accuracy thermometer-decoded current-steering DACs

In this paper, we describe the impact of square and non-square implementations of Current Source Arrays (CSAs) on the integral non-linearity (INL) of the thermometer-decoded current steering Digital to Analog Converters (DACs). The characteristics of several well-known switching sequences have been modeled and simulated using MATLAB in presence of different gradient error profiles. The simulation results show a significant correlation between the efficiency and performance of the employed switching strategy and the physical dimensions of the CSA. Based on the analysis of the obtained results, a strategy is introduced which includes a recursive approach towards the achievement of an optimum switching sequence for distributed current source-based DAC topologies.