Analog Channel Hardware Design Of Synthetic Instrumentation

With concerns growing over the development speed and flexibility of electronic system, of course, high speed, high precise and powerful computing of the instrument is required. While the traditional measuring instruments are limited in their functions, they can not satisfy the various demands of testing and are difficult to extend. Therefore, it is imperative that develop higher performance of comprehensive measurement instrument.Synthetic instrument is a kind of comprehensive measurement instrument,Generally speaking, a Synthetic instrument is based on a common, general purpose, physical hardware platform, and then realizes all kinds of measurement function by virtue of software programming. Thus, compared with traditional instrument its performance has more distinct advantages.The SI research in this thesis is composed of main processor, data acquisition module and arbitrary waveform generator module. With Mpc85 xx series CPU as main processor, this not only can control the data acquisition module to collect data but also can control the arbitrary waveform generator to generate arbitrary waveform. The main research task in this thesis is the design of SI analog channel.In this paper, the SI analog channel mainly includes three modules: digital oscilloscope analog channel, data acquisition signal conditioning module and arbitrary waveform generator signal conditioning module. The main task of this subject is to complete the design of the above three modules and the measurement of the signal conditioning. The research contents include as following:First, the analysis and design of signal conditioning circuit. This circuit mainly completes the input signal attenuation and amplification, filtering the noise signal. Then, the conditioning signal can satisfy the input and output signal range of the ADC and DAC.Second, the design of oscilloscope triggering channel. We can use multiplexer choose one trigger signal, which sent to the high-speed comparator, and then generate the edge-triggered signal. We can realize the function of edge trigger by FPGA.Third, the design of the control circuit. The control circuit mainly completes the state-switch and the level adjustment of the analog channel.Fourth, signal integrity analysis. In this paper, the influence factors of signal integrity are analyzed in detail, and put forward some improvement and perfection measures in the light of these problems.