| 摘要 |
PURPOSE:To easily provide a hysteresis characteristic to the input by connecting a resistor in series with a signal input terminal and connecting a resistor between a level shift input point and a power supply and between the point and ground so as to ensure an output even when transmission lines are short- circuited. CONSTITUTION:The amplitude of a signal inputted to signal input terminals 10, 20 is compressed by the effect of resistors 11, 13 and 21, 23 connected in series between the input terminals 10, 20 and level shift input points 17, 27 and by the effect of resistors 12, 14, 15, 16, 22, 24, 25, 26 connected between a power supply VDD and ground and the potential at the input points 17, 27 is level-shifted in the moving voltage range of a comaprator 30. The input level at input open and input short-circuit is decided by the effect of the resistors 12, 22 connected to the power supply VDD and the resistors 11, 21 connected to the input terminals 10, 20 and the offset caused thereby is eliminated by designing properly the resistors 16, 26 connected between the input points 17 and 27.
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