| Piezoresistive pressure sensor, be made of semiconductor silicon based on piezoresistive phenomenon, has many characteristics of high sensitivity, quick response, high measurement precision, good stability, wide working temperature range and being miniaturized and produced easily. It is a new type sensor developed quickly and used widely. Piezoresistive pressure sensor always faces an important problem of temperature compensation which restricts its applications because of temperature influence on sensor's sensitivity and measurement precision. Therefore, it is a significant project to research temperature compensation for piezoresistive pressure sensor.First of all, state of arts on this topic is reviewed. Some compensation methods are analyzed and their principles are then summarized. The technology about modern signal conditioning which will be used in this paper is also introduced.Signal conditioning chip is in common used for compensation in recent years. Inour research, a set of silicon piezoresistive sensor temperature compensating system based on MAX 1457 is proposed. The total error is limited to 0.1 %FS after being calibrated. MAX1457 is a special sensor signal conditioning chip with high integration. It is mainly used to compensate temperature shift and non-linearity error of piezoresistive pressure sensor. In this paper, the structure of MAX1457 is introduced and relevant math formula is deduced firstly. Then, the idea of compensation design is analyzed deeply based on the character of pressure sensor. Finally, a single-channel compensate module is designed, thus a multi-channel sensor temperature compensating system is developed successfully. The design scheme, circuit and software code are introduced. |
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