An approach to the classification of mixed-signal circuits in a pseudorandom testing scheme

BIST methods based on the application of a pseudorandom pulse sequence as input stimulus have recently been suggested for testing linear time-invariant (LTI) analog parts. In such methods, the input-output cross-correlation function R/sup XY/(t) gives a good estimation of the impulse response of the DUT, h(t), provided the autocorrelation of the pseudorandom input sequence approaches a single Dirac's pulse. In this paper, we focus on the issues related to the choice of a suitable set of samples of the cross-correlation function R/sup XY/(m/sub i/), i=1,..,n, as DUT signature, and, at the same time, to the definition of an effective classification procedure. In particular, we make the choice of the DUT signature on the basis of the sensitivities of the cross-correlation samples to the circuit specifications.