| 摘要 |
PURPOSE:To detect the floating state more accurately by providing a CMOS circuit giving a through-current when a floating detection terminal is in the floating state, a load element causing a voltage drop thereacross by the through- current, and a voltage detection circuit detecting a voltage a voltage caused across the load element. CONSTITUTION:While a signal fed to a floating detection terminal is at '1' or '0' stably, no through-current flows to a CMOS circuit 12 and when the floating detection terminal and a connector terminal 11 of, e.g., an external system are not in contact with each other and only when the signal level supplied to the terminal changes from '1' to '0' or from '0' to '1', the through- current flows to the CMOS circuit 12 and a voltage drop is caused across the load element 13. Thus, only when the potential of the floating detection terminal is in the floating state that the voltage is detected stationarily by the voltage detection circuit. Ths, the floating state is detected accurately.
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