| 摘要 |
PURPOSE:To have assuredly a digital circuit actuated by initializing the digital circuit by the output of a comparator when the output of a differentiating circuit which differentiates the variation of the power supply voltage is higher than the reference voltage of the comparator. CONSTITUTION:When a power supply VCC is applied, the rise voltage is supplied to a differentiating circuit 4 to be differentiated. This differentiated voltage is compared with the comparison voltage Vdif through a comparator 1. When the differentiated voltage value is higher than the voltage Vdif, i.e., during a prescribed period of time after the power supply is applied, the level ''1'' is delivered from the comparator 1 and inverted by an inverter 2 to reset a digital circuit 3. Then the output of the comparator 1 is set at ''0'' level to release the reset state of the circuit 3. The circuit 3 is also reset when the power supply has a short break. Thus it is possible to have assured actuation of the circuit 3 when the power supply is applied and has a short break. |
