Patent ID: 7825666

Claim:
A test apparatus for testing a device under test, comprising: a voltage supplying section that supplies a voltage to a device under test through a wire; a first capacitor that is arranged between the wire and a common potential in series; a current detecting section that detects a current flowing through the wire at a location that is closer to the device under test than the first capacitor is; an integrating section that outputs an integration value obtained by integrating a difference between the current detected by the current detecting section and a predetermined reference current; a judging section that judges whether the device under test is a pass or a failure based on the integration value; and a search section that repetitively varies the predetermined reference current value from test to test to determine an absolute value of the detected current, wherein the search section initially sets the predetermined reference current to a center value of a measurement range of current values to be measured, wherein, upon each judgment of whether the detected current value exceeds the predetermined reference current, it is determined whether the detected current is in an upper range or a lower range of the measurement range, upon the determination the determined upper or lower range is set as a new measurement range, and a new predetermined reference current is set as the center value of the new measurement range, wherein the search section repeats the setting process a plurality of times to narrow the range and determine the absolute value of the current flowing through the wire.