Patent ID: 8774428

Claim:
A MEMS microphone system comprising: a MEMS microphone die including a micromachined electrode and a micromachined structure, moveable with respect to the electrode and configured to establish a capacitance, with respect to the electrode that varies in response to an acoustic signal; a bias circuit configured to be coupled to a power supply voltage, the bias circuit being coupled to at least one of the electrode and the movable structure and configured to apply a bias voltage, no greater than the power supply voltage and less than about 3 volts, thereto, wherein the bias circuit comprises: a voltage reference circuit; and an amplifier coupled between the voltage reference circuit and the at least one of the electrode and the movable structure; a signal processing circuit coupled to at least one of the electrode and the movable structure and configured to process an electrical signal therefrom; and a voltage regulator coupled to the signal processing circuit and configured to provide power thereto, wherein an output signal from the amplifier is coupled to the voltage regulator so as to control the voltage regulator.