| 摘要 |
An integrated, multi-input audio mixer (80) receiving a plurality of analog input signals (Ain-1AinN), internally digitizing the analog input signals, digitally processing and mixing the digitized input signals and producing bo th digital and analog representations of the mixed inputs. All analog inputs (Ain1-AinN) are applied to half of a full delta-sigma analog-to-digital converter. That is, each input is applied to a respective delta-sigma modulator, but all the delta-sigma modulators share a single decimation filt er (89). The output of each delta-sigma modulator controls a respective multiplexer (Mx_1-Mx_N) having a separate input channel for each quantizatio n level of its respective delta-sigma modulator. The output of the multiplexer s is selectively applied to a summing circuit (85). The output from the summin g circuit (85) is applied to a D/A converter (87) to provide an analog output, and is also applied to the single sigma-decimation filter (89), which recove rs the mixed data from the delta-sigma modulators.
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