Circuits and systems

摘要

A temperature-compensated resonant MEMS device comprises a first and second oscillator circuits comprising a first and second resonant MEMS devices and providing a first and second oscillator outputs. One of the resonant MEMS devices is a temperature reference for the other. A level-sensitive mixer circuit has first and second inputs coupled to the first and second oscillator outputs and has a mixer output to provide a signal responsive to a level of the first and second oscillator outputs. The mixer output comprises sum and difference frequency components of the first and second oscillator outputs. A low-pass filter is coupled to the mixer output to attenuate the sum frequency component of the mixer output. An output coupled to an output of said low-pass filter provides a signal responsive to the difference frequency component.