高速数据采集系统中的孔径抖动

研究高速数据采集系统中的孔径抖动对系统信噪比的影响．通过对高速ADC采样保持电路的结构与时域响应的描述，对孔径抖动的成因以及孔径抖动误差与输入信号频率的关系进行了分析，并在此基础上对孔径抖动对数据采集系统信噪比的影响进行了分析与计算仿真．结果表明，孔径抖动引起的孔径误差随着高速数据采集系统输入信号频率的升高而增大，由此将引起系统信噪比曲下降．因此在系统设计中，ADC的孔径抖动及其它可能引入孔径抖动的因素都应给予充分考虑．

Effects of Aperture Jitter to the Signal Noice Ration in High Speed Data Acquisition Systems

Investigates the cause of formation of aperture jitter and its effects to SNR in high speed data acquisition systems. By analyzing the structure of ADC's sample and hold circuit and its response in the time domain, the relation between aperture jitter and frequency of analog input signal is obtained. On the basis of this, by computing and simulating, the effects of aperture jitter to the SNR of high speed data acquisition are made clear. The jitter error brought in by the aperture jitter increases as the frequency increase of the input signal in high speed data acquisition systems, thus it degrades the system's SNR. The aperture jitter of ADC and other factors that introduce the jitter error should be paid enough attention in system design.