| 摘要 |
PROBLEM TO BE SOLVED: To provide a Schmidt characteristic inspecting device, capable of shortening time for inspecting characteristics of a Schmidt input circuit. SOLUTION: This Schmidt characteristic inspecting device 15 is made up of a DA(digital-to-analog) converter 16, a hysteresis width count circuit, and a Schmidt characteristic output circuit 1A. The converter 16 outputs a voltage which is synchronized with a clock signal 1F. The count circuit is synchronized with the clock signal 1F and counts one level section time of a Schmidt output signal 14. For the period of measuring switching voltages Vth, Vtl, the output circuit 1A is set to output the clock only during a period when an output of the Schmidt input circuit is on one level, and after this period, to output the clock equating to the width of a hysteresis, each time the clock signal 1F is inputted. This enables inspection with digital input and digital output.
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