Abstract: A pole-shifted noise shaper whose transfer function has a Z-plane in which the pole has been shifted out of the origin. The noise shaper suppresses idle pattern. The noise shaper has a dither adder (17) placed immediately before a quantizer (16) to add a dither signal to data about to be applied to the quantizer (16). This suppresses attenuation of the dither signal due to noise shaping. Therefore, the dither signal can be supplied effectively. The idle pattern appearing in the output signal can be suppressed. Since the pattern of the dither signal is varied at a frequency that is {fraction (1/16)} to ⅛ of the frequency of the operating clock signal, the frequency of noise component due to the dither signal lowers. The signal and the dither signal component can be easily separated in a rear stage.

Abstract: A pole-shifted noise shaper whose transfer function has a Z-plane in which the pole has been shifted out of the origin. The noise shaper suppresses idle pattern. The noise shaper has a dither adder (17) placed immediately before a quantizer (16) to add a dither signal to data about to be applied to the quantizer (16). This suppresses attenuation of the dither signal due to noise shaping. Therefore, the dither signal can be supplied effectively. The idle pattern appearing in the output signal can be suppressed. Since the pattern of the dither signal is varied at a frequency that is {fraction (1/16)} to ⅛ of the frequency of the operating clock signal, the frequency of noise component due to the dither signal lowers. The signal and the dither signal component can be easily separated in a rear stage.