Non-integrated Intelligent Sensor System Electromagnetic Compatibility

Sensor technology is considered as a synthetical one to realize information detection with kinds of functional material. It is one of the basic technologies to realize information society in the domain of science and technology nowadays.The sensor intellectualization is one of the main aspects about current research on sensor technology, and because of this, the leap of technology and enhancement of economic benefit have come true. Sensor's characteristics have been changed from the sole function and detection to multi-purpose and the multi- variables detection after the sensor technology and intelligent one were united. Also Controlling sensor's characteristic and carrying on the information processing on its own were appeared, which have changed the sensor's characteristic of transforming signal passively. Meanwhile, sensor has been transformed from the isolated device to the systematization and network. The intelligent sensor has become the hot topic of research and development about sensor technology, because of its better appearance on the function, the precision and the reliability.The circuits of intelligent sensor system are complex. Analog and digital circuit coexists and hardware is combined with software in the system. Analog or digital signal is very sensitive to strong disturbance outside when it is transferred from long-distance in industrial environment, also the system itself will produce disturbance. In order to guarantee the intelligent sensor system to work stably and reliably, each kind of disturbance must be suppressed effectively, and the circuit and software design should be optimized.At first the basic concept and theory of EMC, the factors of disturbance and the transmitting routes and the EMC standards are presented in this paper. Then the anti-jamming design of intelligent sensor system is analyzed especially after the concept, functions and ways of making of intelligent sensor system have been introduced. The EMC design of intelligent sensor system has been displaced by the electromagnetic interference and anti- interference design of single-chip computer, signal conditioning circuits, A/D convertor, power supply, multiplex switch and PCB. This paper analyzes the most important condition that could make the sensor system satisfy the electromagnetic compatibility standard is choosing the operational amplifiers which have some certain essential characteristics to constitute circuits. The signal conditioning circuits about Freescale MPX2050 series and ICSensors model 1210 silicon piezo-resistive pressure sensor were designed and the correlative equivalent circuits were simulated in order to validate the conclusions above. At last the PCB of common pressure sensor signal conditioning circuit and MPX2050 amplifier circuit are designed which are followed the rules of EMC design.