| 摘要 |
In order to output an analog signal from which unnecessary out-of-band noise components are appropriately removed in accordance with digital data to be reproduced, a reproduction frequency determination circuit and cutoff frequency selection circuit detect the frequency level of a reproduced signal associated with input digital data and switch an analog LPF to a filter of an appropriate cutoff frequency selected and determined based on the detection result, thereby appropriately removing unnecessary out-of-band noise components from an analog audio signal obtained from the digital data using the filter having the cutoff frequency according to the frequency level of a reproduced signal obtained by reproducing the digital data.
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