| 摘要 |
Analog input signals are supplied to a full-wave rectifier (1) and the peak output of the circuit (1) is held by means of a peak holding circuit (2). A comparator (3) compares the peak output with a reference signal VREF, and the comparator output operates a switch (7). Namely, when the output level of the circuit (2) is lower than the level of the signal VREF (linear amplifying area), one contact (c) of the switch (7) is connected so that the output of a fixed gain delay circuit (6) is outputted as the gain-controlled signal and, when the output level of the circuit (2) is higher than the level of the signal VREF (AGC area), the other contact (d) of the switch (7) is connected so that the output of a VCA circuit (5) is outputted as the gain-controlled signal. |
