A novel capacitive pressure sensor and interface circuitry

A novel capacitive pressure sensor with the island-notch structure is introduced. Its theory model is established based on the structure theory of the plate capacitive pressure sensor. The relationships between the external pressure and capacitance of the capacitive pressure sensor with the island-notch structure are studied by using the method of the finite element analysis (FEA). The results show that the linearity of the capacitive pressure sensor with island-notch structure reached up 0.9941 in the linear measurement zone, the sensitivity reached up 0.0019 pF/kPa, and the measurement range of the capacitive pressure sensor is enlarged. Thus, the contradictory among measure sensitivity, linearity and measure range is effectively relieved in the capacitive pressure sensors with island-notch. In addition, the interface circuitry of the charge transfer is designed, and the performance of the interface circuitry is analyzed.