Patent ID: 7345608
Filing Date: 2008-03-18
Classification: H03M

Abstract:
1. A Delta-Sigma DAC, comprising: an interpolator, over-sampling a n-bit digital signal to generate a n-bit oversampled signal; a Delta-Sigma modulator, coupled to the output of interpolator, shaping the n-bit oversampled digital signal to generate a shaped digital signal; a FIR filter, coupled to the Delta-Sigma modulator, filtering the shaped digital signal to generate an analog audio signal; and an analog filter, coupled to the FIR filter, amplifying the analog audio signal to generate a audible signal; wherein: when the Delta-Sigma DAC powers up, a mute signal is enabled to disable the analog filter, thus the audible signal is not output; and when the shaped digital signal comprises a zero pattern, the mute signal is disabled, and the analog filter is enabled to output the audible signal.