  This paper is devoted to the analysis of resonant MEMS sensors based on
discrete relay feedback techniques. One drawback of such techniques is that
some synchronization usually occurs between the discrete part and the
continuous part of the system: this results in sensor responses that are very
similar to the curves known as devil's staircases, i.e. the frequency does not
vary smoothly with the sensor's input. The main contribution of this paper is a
theoretical calculation of the resolution of such systems. The resolutions of
two existing resonant MEMS architectures are then calculated and these results
are discussed.
