| 摘要 |
PURPOSE:To surely prevent malfunction even with a noise component such as jumping peak or the like in a signal by keeping an input signal to a Schmitt circuit to a potential not reaching the next threshold level for a prescribed time after its output is inverted. CONSTITUTION:A trigger circuit 14 outputting a set signal when an output signal from a Schmitt circuit 14 is inverted, a delay circuit outputting a reset signal at a prescribed time after the set signal is outputted and a sample and hold circuit 13 are provided. The sample and hold circuit 13 keeps the level of the input signal to the Schmitt circuit 14 to a potential where the input signal to the Schmitt circuit 14 does not reach the next threshold level while the reset signal is outputted after the set signal is outputted. Thus, even if a noise component is included in the signal from the pulse generator, malfunc tion of the Schmitt circuit 14 is prevented. |
