Cmos-Compatible Dual-Resonator MEMS Temperature Sensor with Milli-Degree Accuracy

This paper presents a dual-resonator design which, not only enables temperature sensing of the resonators but also acts as a general-purpose temperature sensor. The frequency stability of the temperature compensated resonator depends on the accuracy with which the temperature of the resonator is measured. The dual-resonator design, described here, produces temperature-dependent beat frequency which is inherent to the resonator and thus eliminates any spatial and temporal thermal lag associated with the use of an external temperature sensor. Furthermore, this design can also be used as a CMOS-compatible digital temperature sensor. In this work, we achieved the sensor resolution of approximately 0.008degC which is comparable to that of the best CMOS temperature sensors available today.