A novel wavelet transform based transient current analysis for fault detection and localization

Transient current (IDD) based testing has been often cited and investigated as an alternative and/or supplement to quiescent current (IDDQ) testing. While the potential of IDD testing for fault detection has been established, there is no known efficient method for fault diagnosis using IDD analysis. In this paper, we present a novel integrated method for fault detection and localization using wavelet transform based IDD waveform analysis. The time-frequency resolution property of the wavelet transform helps us detect as well as localize faults in digital CMOS circuits. Experiments performed on measured data from a fabricated 8-bit shift register and simulation data from more complex circuits show promising results for both detection and localization. The wavelet based detection method shows superior sensitivity than spectral and time-domain methods. The effectiveness of the localization method in the presence of process variation, measurement noise and complex power supply networks is addressed.