High-Pressure Performance Evaluation of Crystal Quartz and MEMS Oscillators for Pressure-Tolerant Systems in Deep-Sea Applications

The present study contributes to the ongoing systematic investigation of the output behavior of electronic components in pressure-tolerant systems (PTS). Specifically, this work examines the performance of crystal quartz and silicon-based MEMS oscillators under elevated ambient pressure. A standardised testing methodology was employed, utilizing a fluid-compensated PTS in conjunction with a 600 bar pressure tank to assess frequency stability, amplitude output, and quality factor <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$Q$</tex> under cyclic pressure loads. The results indicate that the output behavior of different types of oscillators, as well as same-type oscillators with varying nominal output frequencies, differs significantly under increased pressure. While crystal quartz oscillators generally exhibit superior signal stability across the applied pressure range, MEMS oscillators demonstrate a more diverse response across their nominal frequency range under repeated pressure cycles. Additionally, the findings highlight possible pressure dependencies in MEMS oscillators, leading to increased frequency and amplitude variations at higher pressures and, in some cases, functional degradation after multiple pressure cycles.