A stereo audio chip using approximate processing for decimation andinterpolation filters

摘要

A stereo audio chip uses approximate processing techniques in thendigital decimation and interpolation filters to reduce its active powerndissipation. One pair of analog-to-digital (A/D) converters and one pairnof digital-to-analog (D/A) converters have been integrated in a die areanof 10.22 mm2 in a 0.5 Μm CMOS technology. The total powerndissipation of these converters without power management is 200 mW whennoperated from a 5-V power supply. When the signal is fully active, powernreductions of 36% for decimation and 17% for interpolation overnfixed-order filters are demonstrated. When the signal is 40 dB belownoverload, power reductions of 67% for decimation and 44% forninterpolation over fixed-order filters are observed. The powernreductions are 83.1% for A/D converters, and 82.7% for D/A converters,nwhen the signal is silent for a period of time