Patent ID: 7764204

Claim:
A digital-to-analog converting system with sampling rate conversions, comprising: an interpolator, for performing an N-times interpolation on a first digital input signal to generate a second digital input signal, wherein a second frequency of the second digital input signal is N times of a first frequency of the first digital input signal; S orders of operating and filtering units, each order of the operating and filtering units comprising: a K-times zero-padding circuit, for performing a K-times zero-padding operation on the second digital input signal to generate a third digital input signal, wherein a third frequency of the third digital input signal is K times of the second frequency; and a filtering circuit, coupled to the K-times zero-padding circuit, for performing a filtering operation on the third digital input signal to generate a filtered digital input signal; an up-converting and down-converting circuit, for performing a B-times up-conversion and an A-times down-conversion on the filtered digital input signal to generate a fourth digital input signal; and a signal processing circuit, coupled to the up-converting and down-converting circuit, for generating an analog output signal according to the fourth digital input signal.