一种测量模数变换器孔径晃动的方法  

Method for Measuring Aperture Jitter of A/D Converter

作　　者：万长春[1] 刘天宽[1] 虞孝麒[1] 

机构地区：[1]中国科学技术大学近代物理系,合肥230027

出　　处：《数据采集与处理》2000年第2期195-199,共5页Journal of Data Acquisition and Processing

摘　　要：孔径晃动是模数变换器 (ADC)的一个重要性能指标 ,但目前还没有一种完善的测量方法。文中提出了一种用两个不同频率正弦信号作输入的频谱累加平均方法来测量实际 ADC孔径晃动 ,分析了测量误差 ,指出了减小测量误差的途径 :在 ADC模拟带宽允许范围内尽可能提高较高一个输入信号频率 ;较高一个输入信号频率选定后 ,另一个输入信号频率尽量低 ;通过增加数据长度和累加次数的方法更精确的估计噪声能量。作者进行了计算机模拟 ,模拟结果验证了上述结论 ,并且表明 ,在计算量不太大的条件下 (10～ 4 0次长度为 10 2 4点的傅立叶变换 ) ,就能达到测量实用 ADC孔径晃动的精度要求。The aperture jitter is an important performance of an A/D converter (ADC). But there is not a perfect method to measure it at present. In this paper a frequency spectrum average method to measure the aperture jitter of a real ADC is proposed in which two sinewave signals of different frequencies are used as inputs. Through the error analysis three ways to reduce the error are pointed out: increasing one of the input signals to a higher frequency in the range of the analog bandwidth of ADC; then lowering the other; and then estimating the noise energy more accurately by increasing the data record length and the accumulating time. The computer simulation result accords with the above analysis, and demonstrates that the precision required in the measurement of the real ADC aperture jitter can be accessed with a fairly small computational effort of 10~40 times that of the 1 024 point FFT.

关 键 词：模数变换器 测量 孔径晃动 计算机模拟 

分 类 号：TP335.1[自动化与计算机技术—计算机系统结构]