Patent ID: 8754694

Claim:
An apparatus comprising: a drive signal circuit for a micro-electromechanical system (MEMS) sensor, the drive signal circuit comprising: an input configured to receive a voltage signal representative of charge generated by the MEMS sensor; a phase-shift circuit electrically coupled to the input and configured to phase shift an input signal by substantially ninety degrees; a comparator circuit with hysteresis, wherein an input of the comparator is electrically coupled to an output of the phase-shift circuit and an output of the comparator circuit is electrically coupled to an output of the drive signal circuit; and a feedback loop extending from the output of the drive signal circuit to the input of the phase-shift circuit, wherein the feedback loop is configured to generate a self-oscillating signal at an output of the drive signal circuit, and wherein an output signal generated by the drive signal circuit is applied to a drive input of the MEMS sensor.