Analysis and measurement of jitter in crystal oscillator

Jitter, as the most important and least understood measure of clock performance in the time domain, is a topic of theoretical and practical interest in electronic circuits, as well as in other fields. For example, jitter is correlated with BER (bit error rate), which is the most important index in communication systems. Although progress has been made in understanding the phenomenon, there still remain significant gaps, both in its fundamental theory and in numerical techniques for its characterization. As phase noise is a representation of jitter in the frequency domain, a companion analysis of phase noise and jitter, mainly random jitter, of a crystal oscillator is presented in this paper. We discuss a method to convert phase noise data to integrated phase jitter. And then, a comparison between estimated jitter from a phase noise plot and its real value from measurements is made, which demonstrates the validity of the method. This method is provided for estimating jitter from phase noise in systems in practice.