| 摘要 |
PURPOSE:To convert a base band signal having a lower frequency component into a digital signal without any error by allowing a cut-off frequency control circuit to increase the cut-off frequency of a DC component eliminating circuit at the start of reception signal input. CONSTITUTION:A one-shot multivibrator 8, an analog switch 9 and a resistor 10 constitute a cut-off frequency control circuit. The cut-off frequency control circuit 8-10 changes the time constant of a DC component eliminating circuit 2 at the start of reception signal input to increase the cut-off frequency. The effect due to fluctuation of the DC component is eliminated in a short time and then the cut-off frequency is restored and even the base band signal having a low frequency component is converted into a digital signal without error. |
