Patent ID: 6795004
Filing Date: 2004-09-21
Classification: H03F,H03M

Abstract:
A delta-sigma modulation device including a quantizer in which an output of the quantizer is fed back to the input side of the device as a feedback signal, the delta-sigma modulation device comprising:a correction circuit for correcting the output including a quantization error of the quantizer, so that a corrected value constitutes the feedback signal, wherein distortion taking place in circuits connected to a succeeding stage of the delta-sigma modulation device is corrected by the correction circuit, wherein the circuits connected to a succeeding stage include a pulse width modulator producing a pulse width modulation signal fed to an amplifier, and wherein the correction circuit includes detecting means for detecting a distortion quantity in the amplifier and producing the corrected value corresponding thereto, and wherein the detecting means includes: rising detecting means for detecting a rising time difference between a rising time point of the pulse width modulation signal and a rising time point of an output signal of the amplifier, falling detecting means for detecting a falling time difference between a falling time point of the pulse width modulated signal and a falling time point of the output signal of the amplifier, calculating means for calculating the distortion quantity in the amplifier from the rising time difference and the falling time difference, and a delay provided at an input side of one of the rising detecting means and the falling detecting means and serving to match a timing between the pulse width modulated signal and the output signal of the amplifier.