Patent ID: 6292124
Filing Date: 2001-09-18
Classification: H03M

Abstract:
A delta-sigma D/A converter comprising:a quantizer for producing a first digital signal of N (N is an integer equal to or greater than 3) output levels at regular sampling intervals;a noise shaper for canceling out low-frequency components of quantization noise produced from said quantizer;a divider for dividing said first digital signal such that it is represented in terms of the sum of output levels of second and third digital signals each indicating an output level obtained by dividing the output level of said first digital signal to a half of the output level or other integer close to the half of it; anda differential amplifier for producing an analog signal corresponding to the output level of said quantizer by subtracting an inverted level signal obtained by inverting a level signal corresponding to said third digital signal from a level signal corresponding to said second digital signal during a former halt of each of said sampling intervals and by subtracting an inverted level signal obtained by inverting a level signal corresponding to said second level signal from a level signal corresponding to said third digital signal during a latter half of each of said sampling intervals.