高速高精度电荷式流水线ADC的转换误差校准方法研究

项目名称： 高速高精度电荷式流水线ADC的转换误差校准方法研究

项目编号： No.61474092

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 张鸿

作者单位： 西安交通大学

项目金额： 79万元

中文摘要： 基于斗链式器件（BBD）的电荷式流水线模数转换器（ADC）是一种新型的无运放A/D转换技术，开辟了低功耗流水线ADC实现的新途径。然而，这种新型ADC的转换精度受到栅自举BBD电荷传输非线性和各子级电容失配所引起转换误差的限制，难以满足新一代宽带通信和雷达等系统的需求。本项目在国家自然科学基金青年基金对电荷式流水线ADC共模电荷误差校准的研究基础上，进一步深入研究电荷式流水线ADC转换误差的校准方法。在对BBD非线性数学建模的基础上，拟分别采用前馈预失真法和数字补偿法校准BBD非线性引起的转换误差；针对各子级电容失配引起的转换误差，拟分别探索基于二分搜索的数模混合校准和纯数字校准方法。在对比各种方法有效性、收敛性和电路开销的基础上，研究确定两类误差校准相结合的总体误差校准方法和电路结构。各种方法的理论分析和推导已初步完成，项目结束时预期在电荷式流水线ADC的转换误差校准方面达到国际水平。

中文关键词： 模数转换器；电荷式；流水线；误差校准；高速高精度

英文摘要： The charge-domain pipelined analog-to-digital converter (ADC) based on bucket brigade devices (BBD) is a novel opamp-less A/D conversion technique, which opens a new way to implement low-power pipelined ADCs. However, because of the conversion errors caused by the nonlinearity in the charge transfer characteristics of BBDs and the mismatches in the capacitors of each sub-stage, the precision of charge-domain ADC is difficult to meet the requirements of next-generation broadband communication and radar systems. Based on the research results from a previous project for common-mode charge error calibration in charge-domain ADCs, which is supported by the the National Natural Science Foundation of China, this project will go a step further to research the calibration methods of conversion errors in charge-domain pipelined ADCs. Based on mathematical modeling of the nonlinearity of BBDs, this project will explore a feedforward predistortion method and a digital compensation method, respectively, to calibrate the conversion errors caused by the BBD nonlinearities. For the conversion errors caused by the mismatches of the capacitors in each sub-stage, this project will adopt a mixed-signal calibration method based on binary search and a pure digital calibration method, respectively. Based on the evaluation and comparison of effectiveness, convergence speed, and consumption of power and chip area for each method, this project will research and determine the overall calibration method and circuit topology that combines the calibration methods for the two kinds of conversion error sources. Theoretical analysis and derivation for each calibration method have been implemented preliminarily, and research productions are expected to achieve international standards in the doamin of ADC design research in the end of this project.

英文关键词： analog to digital converter;charge domain;pipeline;error calibration;high-speed high-precision