| 摘要 |
PURPOSE:To prevent the malfunction of a device after application of a power supply by generating quickly a reset signal after the power supply interruption in an initial reset circuit used for an electronic device. CONSTITUTION:Since a transistor(TR) Q1 is conductive when a power supply is turned on, a TRQ2 is cut off and a potential of a capacitor C12 is increased to a power supply potential VCC with a time constant comprising a resistor R14 and the capacitor C12. The potential of the capacitor C12 is used as a reset signal. Further, a capacitor C11 is charged to nearly the power supply potential via a diode D11. When the power supply is interrupted in this state, the TRQ1 is cut off and the TRQ2 is made conductive because a bias is given thereto by the charge stored in the capacitor C11. Then, the charge in the capacitor C12 is discharged rapidly by the TRQ2 and the reset signal is generated again. |
