非二进制SAR ADC的电容失配校正方法

摘要

The capacitor mismatch problem of 13-bit SAR ADC was studied,and the calibration method based on LMS algorithm was proposed.The influence of capacitance mismatching was analyzed.To reduce the area overhead of high resolution ADC,the segmented capacitance array with redundancy was proposed,which reduced the requirement of capacitance mismatch and provided the conditions for calibration.The calibration method combining DEM technique and LMS algorithm was designed.The model was simulated in MATLAB.The results show that the INL could reach-1.36/1.26 LSB.%研究13比特逐次逼近型模数转换器的电容失配问题,提出结合DEM技术的基于LMS算法的校正方法.分析电容失配对权重的影响,为减小高精度ADC的面积开销,采用冗余结构的分段电容阵列,降低对电容失配的要求,为校正提供条件,设计基于LMS算法的结合DEM技术的校正方法.在MATLAB中搭建模型进行仿真,仿真结果表明,采用校正方法后INL可以达到-1.36/1.26LSB.