Anchor-tilt cancelling accelerometer

An accelerometer, comprising:

• a mechanical structure, comprising:
• a substrate;
• an anchor coupled to the substrate;
• a first proof mass coupled to the anchor by a first flexible member that moves in response to anchor motion relative to the substrate;
• a second proof mass coupled to the anchor by a second flexible member that moves in response to the anchor motion relative to the substrate, wherein the first and second proof masses are aligned about a first axis;
• a first transducer configured to measure a first distance between a first reference area and a first portion of the first proof mass;
• a second transducer configured to measure a second distance between a second reference area and a second portion of the first proof mass;
• a third transducer configured to measure a third distance between a third reference area and a first portion of the second proof mass;
• a fourth transducer configured to measure a fourth distance between a fourth reference area and a second portion of the second proof mass;
• and
• a signal processing circuit coupled to the first transducer, the second transducer the third transducer, and the fourth transducer, the signal processing circuit configured to measure the anchor motion,
• wherein the signal processing circuit produces a first signal proportional to the difference of an output of the first and second transducers and a second signal proportional to the difference of the third and fourth transducers,
• further wherein the signal processing circuit determines a difference between the first signal and the second signal proportional to the motion of the first and second proof masses.