| 摘要 |
PURPOSE:To realize the miniaturization of a device by making such an arrangement that a power supply is maintained so that the output of a power supply circuit is sent to a load circuit for a predetermined period of time even after a power supply switch is tuned off, and also making the capacity of the capacitor of a delay circuit so small as to merely operate an inner circuit. CONSTITUTION:This circuit is provided with a power supply switch for sending out a first signal indicative of the shut-down of power supply when the supply of an input power is stopped and a second switch connected in parallel with the power supply switch 1, and also provided with a power shut-down detection circuit 41 for sending out a second signal indicative of the shut-down of input power supply in response to the first signal and a changeover circuit 6 for limiting the supply of a power supply (d) in response to the second signal, and besides, is provided with a delay circuit 7 sending out a drive signal (b) for opening the power supply switch 2 and a load circuit 5 operating on the basis of the power supply (d) for transmitting and receiving a signal within a predetermined period of time when the second signal is inputted thereto. Thereby, the device can be miniaturized without a capacitor of large capacity is provided. |
