| 摘要 |
PROBLEM TO BE SOLVED: To provide a compression circuit without dispersion in electric characteristic of components and change in characteristic due to an ambient temperature change. SOLUTION: An analog/digital converter 1 applies analog/digital conversion to an input signal, an absolute value calculation circuit 21 obtains an absolute value of an output of the analog/digital converter, a level detection circuit 22 detects a maximum value in the absolute values obtained by the absolute value calculation circuit 21 at least over a half period of the input signal, an attack time release time processing circuit 23 adds a change in the maximum value on the basis of a change as a comparison result between the detected maximum value and the detected level of one preceding sample, the direction in the change, and a predetermined attack time and a predetermined release time, to the maximum value to obtain the detected level of one preceding sample, and a compression arithmetic processing circuit 24 compresses the input signal on the basis of the detected level subjected to the attack time and release time processing. |
