High-precision DAC based on a self-calibrated sub-binary radix converter

A DAC architecture based on a sub-binary radix converter is presented. By calibrating digitally the non-linear sub-binary converter, it is possible to use it as a high-precision, high-resolution, digital-to-analog converter. The analog part of the new DAC doesn't need precise components. It becomes thus possible to build high-performance DACs on a small area, neither requiring aggressive analog design nor highly matched components. By relaxing the constraints on the analog part, this new topology is very promising for the design of high-performance converters with modern technologies. Both digital and analog components are straightforward to design, allowing their automated synthesis by CAD tools. The new converter structure is presented, and the necessary calibration and conversion algorithms are detailed.