US Patent 7293460 Multiple-axis linear accelerometer

A three-axis accelerometer is provided for sensing acceleration in three orthogonal axes. The accelerometer includes a support substrate, fixed electrodes having fixed capacitive plates fixed to the support substrate, and a movable inertial mass having movable capacitive plates capacitively coupled to the fixed capacitive plates. The accelerometer includes banks of fixed and movable capacitive plates oriented to sense acceleration in orthogonal X- and Y-axes. Additionally, the accelerometer includes fixed and movable capacitive plates having a height variation between adjacent plates to sense acceleration in the vertical Z-axis. Input signals are applied to certain electrodes coupled to the fixed capacitive plates, and an output signal is generated on the inertial mass, which is indicative of acceleration in each of the sensing axes. The output signal may be further processed to generate individual acceleration outputs for each of the sensing axes.