Amplitude control for vibrating resonant sensors

A system is provided for controlling the amplitude of a vibrating resonant sensor through a drive signal applied to the resonator. The system comprises a controller that provides the drive signal to a forcer coupled to the resonator to excite the resonator into vibration at its resonant frequency. The system further comprises a buffer having an input node that receives charge of a pickoff capacitor of the resonator that is a measure of the resonator vibration and a current reference waveform. The buffer provides an output that is a difference signal that represents an error of the resonator vibration that corresponds to a difference between the measured resonator vibration and the current reference waveform, wherein the controller adjusts the drive signal in order to null the difference signal.