ΔΣ modulation digital-analog converter, digital signal processing method, and AV device

A ΔΣ modulation digital-analogue converter comprising:

• ΔΣ modulation means including integrating means including at least one integrator for integrating a digital signal, and quantizing means for modulating an output of the integrating means into a quantized signal, the ΔΣ modulation means feeding back the quantized signal to an upstream of the integrating means;
• a switching amplifier for generating a switching pulse in accordance with the quantized signal;
• a low-pass filter for demodulating the switching pulse;
• calculating means for calculating, in accordance with an output of the switching amplifier or an output of the ΔΣ modulation digital-analogue converter, each of compensation values that compensate individually a plurality of possible input values of an input signal which is externally supplied;
• and
• compensation means for compensating the input signal which is externally supplied, based on a compensation value associated with the input signal among the compensation values, and supplying to the ΔΣ modulation means the input signal thus compensated,
• the calculating means working out the compensation value based on magnitudes of a spectrum of odd-order harmonics whose frequencies are A times more than a frequency of the input signal (A is an odd number), the spectrum being obtained in such a manner that an output of the switching amplifier or an output of the ΔΣ modulation digital-analogue converter is subjected to a frequency analysis without a compensation carried out with respect to the input signal by the compensation means.

A digital signal processing method which employs a ΔΣ modulation digital-analogue converter,

• the ΔΣ modulation digital-analogue converter including:
• ΔΣ modulation means including integrating means including at least one integrator for integrating a digital signal, and quantizing means for modulating an output of the integrating means into a quantized signal, the ΔΣ modulation means feeding back the quantized signal to an upstream of the integrating means;
• a switching amplifier for generating a switching pulse in accordance with the quantized signal;
• a low-pass filter for demodulating the switching pulse,
• the method comprising:
• providing, to the ΔΣ modulation digital-analogue converter, storage means in which a first compensation function is stored in advance, the first compensation function indicating a correspondence relationship between each of a plurality of possible input values of an input signal which is externally supplied, and each of compensation values that are individually associated with the possible input values;
• and
• providing compensation means to the ΔΣ modulation digital-analogue converter and compensating, by the compensation means, the input signal which is externally supplied, based on a compensation value associated with the input signal among the compensation values, and supplying, by the compensation means, to the ΔΣ modulation means the input signal thus compensated,
• the first compensation function being set based on a spectrum of odd-order harmonics whose frequencies are A times more than a frequency of the input signal (A is an odd number), the spectrum being obtained in such a manner that an output of the switching amplifier or an output of the ΔΣ modulation digital-analogue converter is subjected to a frequency-analysis without a compensation carried out with respect to the input signal by the compensation means.