Patent ID: 6351835
Filing Date: 2002-02-26
Classification: G01R

Abstract:
A testing apparatus comprising:a test sequence generator for producing at least one sequence of test signals each having a different test pattern; a source current sensor for detecting a source current flowing from a power voltage source to an integrated circuit device under test when the device is subjected to said sequence of test signals; counter circuitry for defining a window period equal to at least one sequence of said test signals; analog-to-digital converter circuitry for sampling the detected source current during said window period and quantizing sampled values of the source current to digital samples; a discrete Fourier transform analyzer for analyzing spectral components of the digital samples to produce a plurality of spectral values at frequencies k/T, where T represents the period of said sequence and k is an integer equal to or greater than unity; and decision circuitry for making a decision on said analyzed spectral values using a plurality of reference spectral values.