| 摘要 |
PROBLEM TO BE SOLVED: To provide a digital attenuating circuit given measures to prevent a substantial occurrences of a reduction in accuracy generated by performing an attenuating process and a reduction in sound quality due to a decrease of dynamic-range when attenuated digital output signal is outputted through an attenuating digital process. SOLUTION: In the circuit, a digital attenuator 5 to perform a digital attenuating process with increasing a data length (16 bits) of a digital signal from a digital signal processing circuit 1 or an A/D conversion circuit 2 selected by an operation of a switching circuit 3 to multiply a predetermined factor to the digital signal is equipped. Furthermore, a wave processing circuit 6 to generate the attenuated digital output signal having an equivalent data length to an original length with performing a rounding process such as a noise shaving process or dither process to bits of a lower part than that of a signal responding to original bits of an output from the attenuator 5 is equipped. |
