| 摘要 |
PROBLEM TO BE SOLVED: To provide a noise cancelling circuit by which quantized noise is considerably reduced. SOLUTION: The noise cancelling circuit 1 is used with a D/A converter including a first modulator 11 and a data output, and includes error measurement devices 12, 13, 14. A filter 19 receives an error signal and produces a filter error signal. A filter compensator 17 is coupled to the data output and provides a compensated output. A scaler 15 is coupled to receive the filter error signal and provides a sealed filtered error signal. A 2nd modulator 16 is coupled to receive the scaled filtered error signal and provides a single bit stream of error data. An summing arrangement 18 sums the single bit stream of error data and the compensated output from the 1st modulator and provides a corrected output, such that the error signal is filtered, scaled and modulated end the data output is compensated such that the corrected output is obtained having a substantially reduced quantization error.
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