Silicon Capacitive Acceleration Sensor And Readout Circuit Design

The acceleration sensor is the key basic component for IMU (Inertial Measurement Unit) to sense and analysis the motion information. With the development of IMU, there is a growing demand for acceleration sensor with excellent temperature stability, resistant to radiation, quick response, low power and small size. As a result of development, there is the tendency of morden inertial accelerometer is micromation and integration. By the known models of the accelerometer,we analysis many facets of how to design a capacitive accelerometer in this paper.In order to calculate the deflection parameters of cantilever beam, a full static, mode and harmonic finite element analysis (FEA) using the ANSYS Finite-Element program is performed. The results derived from FEA are well analyzed for the discipline of structure and its displacement, resonant frequency and mode. By these analyses, optimization design and arts design are performed. Signal processing circuit is the other important facet of design accelerometer. integration need integrate signal processing circuit and accelerometer sensor in a chip, this is vail of restrain the noise and integration. We analysis the noise'effection and design a low noise OTA amplifyier using 2um technology. In a word the designed capacitive accelerater with straight finger electrode structure and the parameter has the maximum measurable acceleration of 70g and allow high disturb of lateral acceleration. This meets the fundmental needs to the realization of micro inertial accelerater with large measurement range. The theory model of this kind of acceleration sensor designed by this paper is founded to guide the fabrication.