| 摘要 |
PROBLEM TO BE SOLVED: To provide an impedance control unit capable of stably executing high-speed tests on semiconductor integrated circuits such as LSIs even in the case that the characteristic impedance of a transmission line on a substrate to be inspected varies due to manufacture variations of the substrate to be inspected and variations of inspection conditions such as temperatures. SOLUTION: In a semiconductor integrated circuit inspecting apparatus, the impedance of a termination resistor 5 connected to a terminal of the transmission line 4 on the substrate to be inspected 3 transmitting an LSI output signal 2 from an LSI 1 is made controllable. On the basis of both the results of comparison between the LSI output signal transmitted through the transmission line 4 and the voltage level of a reference signal 9 of amplitude comparison and the results of comparison between the LSI output signal transmitted through the transmission line 4 and the phase of a phase comparison reference signal 20, the impedance of the termination resistor 5 is controlled in such a way that the degree of matching with the transmission line 4 may lie within a prescribed range. COPYRIGHT: (C)2005,JPO&NCIPI
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