| 摘要 |
PURPOSE:To obtain logical indiscrete values ''1'' and ''0'' of the output signal of an integrated circuit to be tested with only one starting of a test pattern sequence, by providing a circuit for holding maximum and minimum voltage values of the output signal and its scanner in an output signal detecting circuit. CONSTITUTION:A block 7 is a minimum voltage holding circuit and detects the minimum value of logical analog level ''1'' of the output of the integrated circuit (DUT) to be tested, which is inputted through an analog switch 9, for every one pattern, and the minimum value is updated successively and is held. A block 8 is a maximum voltage holding circuit and detects the maximum value of logical analog level ''0'' of the output of the DUT, which is inputted through an analog switch 10, for every one pattern, and the maximum value is updated successively and is held. Thus, it is discriminated that the output signal performs a correct logical operation if the discrimination result of a block 4 is PASS by starting the test pattern sequence only once, and held voltages of blocks 7 and 8 indicate minimum and maximum voltages of logical ''1'' and ''0'' of the output pin on this DUT. |
