Self-testable accelerometer systems

A novel approach to producing a high-reliability silicon accelerometer is described. The approach relies on the electrostatic deflection of the micromachined silicon mass. A number of key advantages result from this configuration. Even though the spring constants of the device may vary from unit to unit or over temperature, and even though the piezoresistive coefficients vary over temperature, as long as the electrostatic voltage and initial separation gap are held constant, the output is proportional to a given acceleration. Applications of this technology are in temperature compensation, testability and unidirectional force-balance applications