| 摘要 |
PURPOSE:To make compact the dynamic range of an analog signal by controlling the amplitude of the analog signal in response to the level of a sample value of a digital signal formed by quantizing the analog signal. CONSTITUTION:The inputted analog signal X is led to a gain control circuit 11, where the signal is amplified by a gain G set in response to a gain control signal Y2 and outputted. This outputted analog signal GX is inputted to a coder (A/D converter) 12 and outputted after quantized. This quantized signal, i.e., a digital signal X0 is recorded and reproduced in a digital signal or processed for signal. Further, the said signal X0 is led to an amplitude detecting circuit 13, where the said signal Y2 is produced. The circuit 13 receives the gain control signal Y2 in response to the amplitude of Y1 so as to provide a small gain when the amplitude of the value Y1 of the signal X0 is large and to provide a large gain when the amplitude of the value Y1 is small. Thus, the dynamic range of the analog signal is made compact between the input and output of the circuit 11. |
