Patent ID: 9304155
Filing Date: 2016-04-05
CPC Classification: G01C,G01D,G01R

Claim Text:
1. A MEMS capacitive sensing interface comprising: a sense capacitor having a first terminal and a second terminal, the sense capacitor having associated therewith a first electrostatic force; a feedback capacitor having a third terminal and a fourth terminal, the feedback capacitor having associated therewith a second electrostatic force, the second and the fourth terminals coupled mechanically and electrically to a movable common mass, a net electrostatic force comprising the first and second electrostatic forces acting on the common mass, wherein in response to a change in position of the movable common mass, the sense capacitor being operable to output a signal indicative of the change in position and the feedback capacitor being responsive to the output signal; and a capacitance measurement circuit operable to measure the sense capacitance and to couple the first terminal and the third terminal, the capacitance measurement circuit, the sense capacitor, and the feedback capacitor defining a feedback loop operable to substantially eliminate dependence of the net electrostatic force on a position of the movable common mass.