The Research Of Digital Calibration For A/D Converter

In recent years, the development of video signal processing and portable communications technology rapidly, they need to use high-speed high-precision A/D converter, while the traditional types of A/D converter is difficult to simultaneously meet their requirements for speed and accuracy. Pipeline structure of the A/D converter to better meet the system requirements for speed and accuracy, well adapted to the needs of technology development has become used in video processing of the A/D converter mainstream.Based on the analysis of the pipeline A/D converter in the formation of the reasons for the error and the pipeline A/D converter performance effects, for the comparator offset and gain mismatch of amplifier propose appropriate solutions. Based on the pipeline A/D converter quantization method and the formula derived by, for digital correction technique provides the theoretical basis, at the same time demonstrate the correctness and the advantages of digital correction algorithm. And then based on digital correction algorithm, respectively, described for the offset correction and gain mismatch of amplifier calibration principle and circuit implementation form, and that they be expanded. Introduced the other structures of the digital correction circuit features, advantages and disadvantages and the method of digital correction techniques combined with the actual circuit. Finally, according to the figures mentioned in this article correction techniques, to build a 10-bit digital correction circuit, through the functional simulation to verify its functionality.