Digital calibration technique based AC injection for continuous-time sigma-delta converters

In this study, a digital calibration method applicable for a continuous-time sigma-delta analogue-to-digital converter is proposed using the AC injection technique. The proposed technique directly calibrates the integration accuracy of a converter instead of only trimming the capacitors. Compared with the existing calibration methods, the proposed method does not require complex timing logic processing or additional capacitors and does not adversely impact the dynamic performance of the converter. Furthermore, it ensures the accuracy of the converter, regardless of the non-ideal effects of advanced processes. The proposed method does not require complex timing logic processing or additional capacitors and does not adversely impact the dynamic performance of the converter. Furthermore, it ensures the accuracy of the converter, regardless of the non-ideal effects of advanced processes.image