Sensor having an off-frequency drive scheme and a sense bias generator utilizing tuned circuits

Apparatus comprising:

• a sensor having a resonant frequency;
• an electrostatic element responsive to a drive signal having a second frequency for generating a force signal having a component at said resonant frequency to excite said sensor, wherein said second frequency is greater than said resonant frequency;
• and
• a tuned circuit comprising at least one capacitor and at least one inductor for amplifying said drive signal provided to said element.

A method for sensing a stimulus comprising the steps of:

• generating a force signal having a first frequency by applying a drive signal having a second frequency greater than said first frequency to an electrostatic element;
• electrostatically actuating a sensor subjected to said stimulus and having a resonant frequency substantially equal to said first frequency with said force signal;
• detecting a response of said sensor to said stimulus;
• and
• amplifying said drive signal with a tuned circuit comprising at least one capacitor and at least one inductor.

A sensor system comprising:

• an actuator having an admittance and receiving a drive signal;
• a sensor responsive to said actuator and to a stimulus for producing an output signal;
• an electrode biased by a sense bias voltage for sensing said output signal;
• and
• a tuned circuit for amplifying at least a selected one of said drive signal and said sense bias voltage, said tuned circuit having an admittance, wherein said admittance of said actuator is substantially negligible with respect to said admittance of said tuned circuit.