Analog Circuit Diagnostic System With A Filter Algorithm Based On Cosine-modulated Sub-realization

The analog circuit fault diagnosis usually has been the active topic in test field. However, compared to the achievements at digital circuit fault testing of the last four decades, the development of analog circuit fault diagnosis is too slow. The performance of analog circuit is very sensitive to the parameter values of device in circuit, and the fault of analog circuits are usually divided into soft-fault (or parametric failure) and hardware failure (or disaster type failure).In this paper, two analog circuit fault diagnosis systems are separately realized utilizing TEK oscilloscope, PC and MATLAB platform and based on the TMS320F2812DSP chip, which are both based on cosine-modulated subband filtering algorithm and implementation using different platforms.Through many experimental statistics and debugging, we eventually make the two sets of analog circuit fault diagnosis system run well and truly. The restriction that simple use of cosine-modulated subband filtering algorithm could be hard to actualize the fault diagnosis is broken because of importing the concept of weights coefficient for sub-band, which sets a solid foundation for the using of the system in future make the analog circuit fault diagnosis system based on TEK oscilloscope, PC and MATLAB platform be able to reach a higher diagnostic efficiency.This paper introduces the background and the development status of the analog circuit fault diagnosis at first, and then introduces how to realize the prototype filter and sub-band filter banks and the cosine-modulated subband filtering algorithm. It also gives brief description of fault model selections and settings of the inspected analog circuit, thirdly introduces the realization and the actual test results of the two analog circuit fault diagnosis systems separately based on TEK oscilloscope, PC and MATLAB platform and TMS320F2812DSP chip. Finally the paper summarizes a conclusion on the process and ideation of this design and gives some follow-up improvements.