| 摘要 |
PURPOSE:To prevent an unnecessary pulse from being outputted to the outside by stopping an operation of an output section if a power supply voltage drops to the operating guarantee range of a digital circuit or less. CONSTITUTION:A voltage dividing ratio of a voltage divider 4 is set to make a transistor(TR) 7 nonconductive, if the power supply voltage Vcc drops to the operating guarantee range of the digital circuit or less. Then, when the power supply voltage drops to the operating guarantee range or less, the TR7 is nonconductive and since no current flows to a photodiode of a photocoupler 5 even if a TR6 is conductive with an unnecessary pulse from a logical section 3, no signal is outputted to an output terminal 8. Thus, the output of the unnecessary pulse to the outside is prevented in such a way. |
