Low-Power Dual Mode MEMS Resonators With PPB Stability Over Temperature

We demonstrate two novel dual-mode ovenized MEMS resonators, each with an in-chip device layer micro-oven that utilizes less than 30mW for resonator temperature control over variations in external temperature from −40°C to +60°C. The device layer micro-oven enables correction for ambient temperature variations and achieves a 1-week frequency stability for the output mode over temperature near 1.5 ppb for the Lamé-mode resonator. The devices were built in the Epi-Seal fabrication process and take advantage of the exceptional long-term stability of MEMS resonators built in that process. These results exceed all prior reports for frequency stability over time and temperature for MEMS resonators and have the potential to impact the development of miniature, low-power time references. [2019-0054]