时钟抖动测量方法

研究了时钟抖动的测量方法，并根据时钟抖动与ADC采样信号信噪比之间的关系，提出利用信噪比测量时钟抖动的两种方法：（1）通过信噪比与信号频率之间的关系计算时钟抖动的频率扫描法；（2）通过信噪比与信号幅度之间的关系计算时钟抖动的幅度扫描法。同时利用Matlab分别对两种方法进行了仿真和验证。最后用这两种方法分别测量了锁相环时钟和晶振时钟的抖动。测量结果表明，频率扫描法、幅度扫描法测量时钟抖动操作简单、测量精确，并且具有很好的一致性。

Clock Jitter Measurement Method

Measurement methods for the clock jitter are reviewed, and two new methods for measuring the clock jitter are put forward based on the relationship between the input clock jitter and the signal-to-noise ratio(SNR) of the signal sampled by an ADC:(1) The frequency-scanning method based on the relationship between the SNR and the signal frequency;(2) The amplitude-scanning method based on the the relationship between the SNR and the signal amplitude.Two methods are simulated in Matlab,and the actual jitters of a PLL clock and a crystal oscillator clock are measured.Measurement results show that the frequency-scanning and the amplitude-scanning methods are easy,accurate to measure the clock jitter,and have a good consistency.