摘要
模数混合信号电路已成为未来电路设计的发展趋势,对模数混合电路诊断和测试方面的需求日益急迫。文章首先针对模拟/数字混合电路的故障诊断,基于小波分析理论,提出了动态电流(IDDT)测试方法。其次应用小波变换的时频分析特性,对模拟/数字混合电路正常模式和故障模式的IDDT采样信号进行小波分解,得到特征小波系数,计算出正常模式和故障模式下相应特征小波系数的均方根误差。最后将待检测电路的特征小波系数均方根误差与已知正常及故障模式的特征小波系数均方根误差进行比较,根据结果的异同实现模拟/数字混合电路的故障诊断。通过仿真实验验证了该测试方法的有效性,与传统单一时、频域(FFT)诊断分析方法相比,仿真结果显示,该方法对模拟/数字混合电路的故障有较高的检测灵敏度,可以实现绝大多数故障的准确定位,为模拟/数字混合电路故障的准确诊断提供了一种有效手段。
As the analog/digital hybrid circuit is becoming one of the trends of the future circuit design ,the demand for the troubleshooting and testing of the analog/digital hybrid circuit becomes increasingly urgent. This paper proposes a transient current（IDDT）testing method for the fault diagnosis of analog/digital hybrid circuit. Based on the time-frequency resolution property of wavelet transformation,wavelet decomposition is applied to the sampled signals of dynamic current in the normal mode and the fault mode of the analog/digital hybrid circuit so as to get the wavelet coefficient and calculate the coefficient＇s root-mean-square error（RMSE）in the two modes. By comparing the RMSE of the tested IDDT with that in the known normal and fault modes,the fault of the ana- log/digital hybrid circuit can be diagnosed. The simulation result on a 2-bit flash ADC circuit demonstrates the proposed method is valid and has a higher sensitivity in fault detection than the traditional methods. The simulation result also implies the method is able to effectively localize the fault regions in analog/digital hybrid circuit.
出处
《常州工学院学报》
2013年第1期33-36,共4页
Journal of Changzhou Institute of Technology
基金
2012年度安徽高校省级自然科学研究项目(KJ2012Z261)
关键词
模拟
数字混合电路
故障诊断
小波变换
电流测试
analog/digital hybrid circuit
fault diagnosis
wavelet transform
current testing
