Patent ID: 7281181
Filing Date: 2007-10-09
Classification: G01R

Abstract:
1. A method for calibrating an automated circuit test system, comprising: electrically coupling a first calibration unit between a plurality of drivers and comparators of the test system, the first calibration unit comprising fixed wiring paths that couple the drivers and comparators to form a first set of signal paths between a first set of driver and comparator pairs; executing a resistance check while the first calibration unit is coupled between the plurality of drivers and comparators, thereby determining resistances for the first set of signal paths; electrically coupling a second calibration unit between the plurality of drivers and comparators, the second calibration unit comprising fixed wiring paths that couple the drivers and comparators to form a second set of signal paths between a second set of driver and comparator pairs; executing a resistance check while the second calibration unit is coupled between the plurality of drivers and comparators, thereby determining resistances for the second set of signal paths; and solving a set of equations based on the resistances and the first and second sets of driver and comparator pairs to determine i) relative resistances imparted by signal paths of the test system that include the drivers, and ii) relative resistances imparted by signal paths of the test system that include the comparators.