DATA PROCESSOR, PROGRAM AND RECORDING MEDIUM, AND PULSE WIDTH MODULATION DEVICE USED THEREFOR

摘要

PROBLEM TO BE SOLVED: To realize a pulse width modulation device which outputs a pulse width modulation signal less in waveform distortion at the time of demodulation without reducing the pulse period of the pulse width modulation signal. SOLUTION: A distortion correction processing part 31 outputs a signal obtained by subtracting (Δa/2)2/2 from the current digital data, whereΔa is the absolute value of an extent of inclination on the waveform of the current digital data. A noise shaper 22 outputs 47-stage data to a pulse width modulation processing part 21 after subjecting the signal to noise shape processing, and the pulse width modulation processing part 21 outputs a pulse width modulation signal which has a pulse width according to the data and has fixed time intervals of the center positions of pulses. Though a demodulation signal of the pulse width modulation signal is distorted by pulse width modulation in the pulse width modulation processing part 21, a component in a direction opposite to this distortion is added to cancel the distortion by correction in a distortion correction processing part 31. COPYRIGHT: (C)2004,JPO