| 摘要 |
PURPOSE:To shorten the level detection time by connecting an overshoot generating circuit with the pre-stage of a low pass filter so as to shorten the time till the detection output reaches a threshold voltage. CONSTITUTION:The overshoot generating circuit is connected in series with an input signal and a detection circuit 2, a low pass filter 3 and a comparator 4 are connected succeedingly. The comparator 4 compares a detection output S0 from the low pass filter 3 with a reference threshold voltage Vth to detect the level. Thus, even when the input signal level is small and the detected output S0 exceeds the threshold voltage Vth slightly, since the input signal waveform overshoots, the leading is made quick. Thus, the arrival time t0 of the detection output till the threshold voltage is shortened. |
