一种基于时间偏差的动态比较器失调电压校正方法  

Calibrations of offset voltages in dynamic comparators using time-skew

作　　者：苏易博 王芳[1,2] SU Yibo;WANG Fang(Henan Normal University,Xinxiang 453007,China;Henan Key Laboratory of Optoelectronic Sensing Integrated Application,Xinxiang 453007,China)

机构地区：[1]河南师范大学,河南新乡453007 [2]河南省光电传感集成应用重点实验室,河南新乡453007

出　　处：《微电子学与计算机》2024年第7期64-73,共10页Microelectronics & Computer

基　　金：国家自然科学基金(62075057,62075058)。

摘　　要：低失调电压是高速高分辨率动态比较器设计中最为关键的指标之一。现有的失调电压的分析模型和校正方法都是基于传统的电压、电流和负载的维度,忽视了动态比较器时间域维度失配引入的失调电压。针对该问题,提出了一种非平衡电流充放电理论模型。对比传统分析模型,提出的新模型不受电路直流工作点限制,且可以覆盖电压、电流、负载和时间全维度失调电压产生机理的分析。基于该模型分别对3种典型失配机理产生的失调电压进行量化分析。同时,根据时间域失配机理分析提出了一种新的基于时间偏差的高能效失调电压校正方法,相较于传统电压补偿或负载补偿的方法,新的校正方法不是通过改变比较器充放电曲线的斜率补偿失调电压的影响;而是通过改变比较器充放电曲线的开启时刻补偿失调电压的影响。根据65 nm CMOS工艺设计实例的蒙特卡洛仿真结果,新的失调电压校正方法的校正精度可以从传统的小于几毫伏精度提升到小于0.5 mV精度,同时无需额外复杂辅助电路,更适用于高速高能效动态比较器的设计实现。Low offset voltage is a critical design specification of high speed and high resolution comparator.The conventional analysis models and calibration methods for offset voltage are based on the dimensions of voltage,current and load,ignoring the offset voltage introduced by the time domain dimension mismatch of the dynamic comparator.To solve this problem,an unbalanced current charging and discharging theory model is proposed.Compared with the conventional one,the new one is not limited by the DC points,and covered voltage,current,loading and time.Three typical mismatch mechanisms have been analyzed based on this model.Meanwhile,a high energy efficient calibration method using time deviation is proposed based on the analysis of time mismatch mechanism.Compared with traditional voltage compensation or load compensation calibration methods,the traditional calibration methods change the slope of the comparator's charging and discharging curves.The new calibration method changes the start time moment of the comparator's charging and discharging curves.According to the design example based on 65 nm CMOS technology,the accuracy could be improved from less than a few millivolts to less than 0.5 mV compared to traditional methods.The new method doesn't need extra and complex circuits,which is more suitable for the high-speed and high-energy efficient dynamic comparator design.

关 键 词：动态比较器 动态失调电压 静态失调电压 时间偏差 模数转换器 

分 类 号：TN432[电子电信—微电子学与固体电子学]