Low-power ovenization of fused silica resonators for temperature-stable oscillators

In this paper, we report on temperature-stable operation of silica MEMS oscillators on an ovenized fused silica platform. Temperature servo-control circuits are implemented using an on-chip RTD-based temperature sensor and a resistive heater. A wide-range linear analog controller has been implemented to reduce the effective TCF of the fused silica resonator by an order of magnitude. Digital calibration method is used to mitigate offset errors caused by non-ideal temperature sensing. By effectively removing the offset errors, the frequency drift of an oscillator using a silica micromechanical resonator is reduced to less than 11 ppm over 105 °C of external temperature change. The power consumption to ovenize the entire platform consisting of four resonators is lower than 15.8 mW.