| 摘要 |
<p>PURPOSE:To easily obtain a CPU reset circuit with high reliability by using a voltage detecting circuit and a discharging element. CONSTITUTION:The secondary power voltage A applied from a power circuit 11 is inputted via a terminal 5. When the voltage A is applied to a reset circuit through a voltage detecting circuit consisting of a transistor TR 12, the resistors 15 and 16, and a Zener diode 13. Thus the value V of the voltage A can be changed when the Zener voltage of the diode 13 is set in accordance with the power characteristic of a device. A discharging resistor 14 drops quickly the voltage of the RESET terminal of a CPU 1 when the TR 12 is turned off. As a result, a stable reset signal is always supplied to the CPU 1 regardless of the power characteristic at the time of turning on/off of the power supply. Thus it is possible to easily obtain a CPU reset circuit with high reliability.</p> |
