DETECTOR FOR WAKE-UP SIGNAL

摘要

PURPOSE: A wakeup signal detector is provided to detect a wakeup signal using a counter and a plurality of integrating circuits. CONSTITUTION: A signal determining unit(20) determines whether the output of an amplifier is a continuously normal wakeup signal for a preset time. A counter(25) counts a signal inputted from the signal determining unit. If the count number of the counter reaches a preset value, a buffer circuit(30) outputs a wakeup signal. If the count number stays at a previous count number before the count number of the counter reaches the preset value, an integrating circuit(35) clears the counter.