| Summary: | 碩士 === 義守大學 === 電子工程學系 === 92 === Micro pressure sensors are widely used in automotive and aerospace industries. Most of these sensors function on the principle of mechanical deformation and stresses of thin diaphragms induced by the measured pressure. Mechanically induced diaphragm deformation and stresses are then converted into electrical signal output through several means of transduction. Because of the well-established electronic characteristics and excellent mechanical properties, silicon is used for mechanical sensors. Interest in the mechanical properties of silicon and its use for sensors started with the discovery of its piezoresistivity. Other advantages of silicon include drastically reduced dimensions and mass, batch fabrication and easy interfacing or even integration with electronic circuits and microprocessors. The major factor affecting the high performance applications of the piezoresistive pressure sensor is the temperature dependence of its pressure characteristics. The influence due to temperature variation is manifested as a change in the span, bridge resistance, and offset of the sensor. In order to reduce the thermal drifts of the offset and span of the piezoresistive pressure sensor, a Half-Bridge-Compensation (HBC) technique is presented in this thesis. Many advantages will be shown in this thesis, such as the temperature compensation of the sensor (typically lower than 1%), and a simple and low cost application circuit. The theoretical analysis and experimental results show that both the output voltage and zero offset drift are much improved by the first-order HBC technique. The experimental results are matched to our theoretical analysis.
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