Noise-induced Synchronization of Crystal Oscillators

Abstract

Experimental study on noise-induced synchronization of crystal oscillators is presented. Two types of circuits were constructed: one consists of two Pierce oscillators that were isolated from each other and received a common noise input, while the other is based on a single Pierce oscillator that received a same sequence of noise signal repeatedly. Due to frequency detuning between the two Pierce oscillators, the first circuit showed no clear sign of noise-induced synchronization. The second circuit, on the other hand, generated coherent waveforms between different trials of the same noise injection. The waveform coherence was, however, broken immediately after the noise injection was terminated. Stronger modulation such as the voltage resetting was finally shown to be effective to induce phase shifts, leading to phase-synchronization of the Pierce oscillator. Our study presents a guideline for synchronizing clocks of multiple CPU systems, distributed sensor networks, and other engineering devices.