针对集成电路测试中模拟和混合电路的测试问题,提出了一种基于小波分析的电流测试实现混合信号电路故障诊断的方法。该方法先测试电路在激励信号下的动态电流,再利用小波变换对采样动态电流信号进行小波分析来诊断电路是否存在故障,并进一步定位故障。对示例ADC电路仿真试验的结果表明该方法比积分法和傅立叶分析方法对故障有更高的灵敏度,不仅能够有效检测出电路中的各种故障,而且能对故障进行定位。
How to test the analogue and mixed-signal circuits has become very critical to the IC testing, a novel fault diagnosis method based on current testing is proposed for mixed-signal circuits. This method measures the dynamic current of circuits under test, and decomposes the sampled current signature with wavelet transform. To detect and localize the faults, the wavelet coefficients of current signature are analyzed to extract the fault characteristic information. The experimental results for an ADC circuit show that the presented method have higher sensitivity to fault than the pure integral and FFT method, and can not only defect faults effectively, but also localize the faults satisfactorily.