Reserch On Key Techniques Of Analog Input Channels In Instruments

As the development of technology, electron measurement is becoming more and more important in the scientific research and application of engineering. Electron apparatus is the basic tool which is used to implement electron measurement. And the range and precision are determined by performance of electron apparatus's front analog input circuit. Although it is well developed abroad, the research of this aspect is behindhand in our country. So, it is of great importance in research of electron apparatus's front analog input circuit.The main function of electron apparatus's front analog input circuit is discussed in this thesis. Based on the abundant investigation and detailed analysis of the circuit requirements, the overall scheme of electron apparatus's front analog input circuit is established. Then the design method of analog circuit based on EDA software simulation and optimization is presented. The associated key technology of electron apparatus's front analog input circuit is deeply researched, including high frequency circuit theoretic and high speed amplifier.To assure the reliability of match and transmission, matching and attenuation network withПstyle and nondistortion transmission network are used in the design of matching and attenuation network with 50 ohm and 1M ohm. Combined with wide band current feedback amplifier, FET input circuit and programmable circuit, variable gain amplification circuit with high speed and high input impedance is designed. It is simulated and optimized based on the method of EDA software. The parameter of different devices is calculated with optimum performance and higher yield.At last, the experimental results of electron apparatus's front analog input circuit show that the design of analog circuit according to the method described in this thesis can satisfy the requirements of the design.