Defect Oriented Testing of Analog Circuits Using Wavelet Analysis of Dynamic Supply Current

In recent years, Defect Oriented Testing (DOT) has been investigated as an alternative testing method for analog circuits. In this paper, we propose a wavelet transform based dynamic supply current (IDD) analysis technique for detecting catastrophic and parametric faults in analog circuits. Wavelet transform has the property of resolving events in both time and frequency domain simultaneously unlike Fourier transform which decomposes a signal in frequency components only. Simulation results on benchmark circuits show that wavelet transform has higher fault detection sensitivity than Fourier or time-domain methods and hence, can be considered very promising for defect oriented testing of analog circuits. Effectiveness of wavelet transform based DOT amidst process variation and measurement noise is studied.