Patent ID: 6144214
Filing Date: 2000-11-07
Classification: G01R

Abstract:
A built in current sensor circuit for use in testing integrated circuits for defects by sensing current increases caused by the defects, said built in current sensor circuit comprising in combination:detecting means for detecting circuit flow through the integrated circuit and providing a representative signal therefor, said detecting means comprising a detecting transistor that produces the representative signal;reference source means for providing a reference threshold signal, said reference source means being electrically coupled relative to said detecting means;comparator means for comparing the reference threshold signal to the representative signal, said comparator means being electrically coupled to said detecting means and electrically coupled to said reference source means;said reference source means comprising a current generating transistor electrically coupled to a voltage level setting transistor, whereby the voltage level setting transistor is electrically coupled to said comparator means, said detecting transistor having process parameters that match the process parameters of said voltage level setting transistor;and an active output load electrically coupled to said comparator means, said active output load being sized to draw a disproportionately larger current when turned on than the current caused by the defect in the integrated circuit,whereby said comparator means turns on said active output load when said representative signal is determined to be larger than said reference threshold signal and the current draw of the active output load is resultantly sensed indicating that the integrated circuit is defective.