| 摘要 |
PROBLEM TO BE SOLVED: To obtain a level detection circuit with small errors when a level is detected and to obtain the communication device that uses the detection circuit with high detection level accuracy. SOLUTION: A level detector 1 detects the level of a signal, and a peak-hold circuit 2 bolds a peak level of the level detector 1. A time constant circuit 4 uses a prescribed time constant for a charging time constant of the peak hold circuit 2, a time constant circuit 5 uses a prescribed time constant for the discharge time constant of the peak hold circuit 2, and an integration device 3 integrates an output of the peak hold circuit 2. With this the configuration, the peak hold circuit 2 whose charge/discharge time constant is set to an optimum value holds an output of the level detector 1, and the integration circuit integrates the held output and provides an output. Thus, even when there is a fluctuation in an envelope in an input signal, a level detection errors can be reduced. |
