Measurement of noise characteristics of MEMS accelerometers

Microelectromechanical systems (MEMS) are devices that have static or movable components with dimensions on the scale of a micrometer. One particular device that is widely used commercially is the MEMS accelerometer. Such accelerometers typically contain some movable micro beams that measure acceleration in one or two orthogonal directions. Major markets for MEMS accelerometers are automobile airbag triggers, earthquake detection circuits and health care. MEMS accelerometers have advantages over conventional accelerometers because they are smaller, lighter and cheaper. Since MEMS accelerometers are used in many systems, the noise characteristics of these devices are very important. The noise characteristics will influence the performance of the accelerometers especially when operating at lower g conditions. In this work, we report on the noise characteristics and special measurement techniques for Analog Devices ADXL202, ADXL 105 and ADXL 190 accelerometers.