| 摘要 |
PURPOSE:To remove nonlinear distortion based upon an excessive input by level- compressing a digital signal in case that a digitized code pattern of not less than a fixed level is input. CONSTITUTION:A code pattern of a digital signal arriving from input terminal 1 is supervised by peak detecting circuit 3 and level detecting circuit 6 and when a digital level of not less than a maximum level that the device can process arrives, attenuation characteristics are provided to multiplier 9 in accordance with the value of the excessive level. The attenuation characteristics are given by coefficient unit 8 composed of ROM in accordance with the excessive level. Then, the input digital signal is delayed by delay circuit 2 by the time that the circuit requires for attenuation and since the attenuation is carrier out by fixed time-constant circuit 4, the excessive input signal can smoothly be attenuated, so that an overflow can be prevented. |
