A start-up calibration method for generic current-steering D/A converters with optimal area solution

This paper presents a new start-up calibration method for current-steering D/A converters, based on a 1-bit ADC. The paper proposes a new current cell that allows calibration of non-identical current sources by way of a shared calibration apparatus. The current cell uses parallel self-calibrated unit elements. Each of these is calibrated individually and when all combined together, the accuracy of the current sources is improved. This method is independent of the DAC architecture and hence an extra degree of design freedom exists. A minimal area solution can be found through optimizing the calibration strength, since the method is not only applicable to the identical thermometer current sources of the segmented DACs. A general discussion on the new calibration method is offered and conclusions are drawn.