ANALYSIS OF ELECTROSTATIC-DAMPED PIEZORESISTIVE SILICON ACCELEROMETERS

A new method of achieving an accelerometer with the desired damping va lue based on electrostatic forces over the seismic mass is analyzed. T his method avoids the temperature dependence of the damping and allows its accurate control after the encapsulation process, even though the mechanical performance of the device may vary from unit to unit. It a lso permits self-testing and calibration of the accelerometer. The cha racteristics of this accelerometer have been simulated using FEM and a n equivalent electrical circuit. A detailed analysis of the useful ran ge and stability behaviour compared with classical viscous damping is also presented.