Research On Integrated Sensor Chip Of Temperature And Pressure

Tire Pressure Monitoring System (TPMS) is a kind of system which monitors the tire pressure through the pressure sensor imbedded into the tires of the car. It is used to prevent the traffic accidents from abnormal tire pressure. So it is significant to research and develop such system for driving safety.This paper describes a design and fabrication of integrated sensor chip for TPMS based on Si₃N₄ membrane, which include temperature and pressure sensor. Considering MEMS processing compatibility, Pt resistance is used to measure temperature and strain gauge to measure the pressure. This design has the advantages of simple structure and easy processing. The characteristics of the sensor have been calculated and simulated. The integrated sensor chip of temperature and pressure is made out and several processing techniques are experimented.This paper also designed a measure system to finish the characteristics measure of integrated sensor chip of temperature and pressure. The accuracy of temperature sensor is 0.1 ℃ and the accuracy of pressure sensor is 3hPa. Based on the test results, the analysis of the temperature affect to pressure is done and the theory calculation is given. Two kinds of temperature compensation are designed.Based on the integrated sensor designed in this paper and using CC1020 as RF unit and C8051Fxxx as MCU, a low power consumption circuit system is designed. The characteristics of the circuit system are tested and the lifetime also calculated approximately. The RF power of the system can reach 10dBm and the lifetime is about 4.5 years ideally.