| 摘要 |
PURPOSE:To improve the sound quality of a PCM system processor by limiting the amplitude of an input analog signal so that the input signal does not exceed the permissible value of a voltage inputted to an AD converter. CONSTITUTION:Amplitude limiter 10 is that provided in front of LPF1 and limits the amplitude of an input analog signal so that the input signal does not exceed the permissible value of an input voltage to AD converter 3. In this case, when input signal Vin is between Vm and +Vm, output Vout appears as it is and once the absolute value of input signal Vin exceeds Vm, the output amplitude is kept constant as output Vm. Consequently, the sound quality can be improved by preventing a usually generated return noise at the time of an excessive input noise. |
