Subband filtering for time and frequency analysis of mixed-signal circuit testing

A new technique is proposed to analyze and compress the output responses from analog circuits. We first describe the subband filtering scheme to decompose responses from the analog circuit under test (CUT). A subband or wavelet filter takes the response, then generates the decomposed signals for each frequency band. The decomposed signal for each frequency band is rectified and then fed into its respective integrator. Two kinds of wavelet filters are used to decompose the test response and effectively detect the faults in the circuit. Implementation issues including hardware overhead are also discussed.