| 摘要 |
Methods of and apparatuses for optimizing quantization noise cancellation in multi-phase sampled MASH ADCs are disclosed. A test signal is combined with quantization noise produced by a delta-sigma modulator. Two parallel adaptive filters (i.e. even and odd filters) are configured to receive respective even and odd samples of a digital output signal of a MASH ADC analog modulator. Adaptive coefficients for the even adaptive filter are derived from correlation results between the even samples of the test signal and associated even samples of the final digital output signal. Similarly, adaptive coefficients for the odd adaptive filter are derived from correlation results between the odd samples of the test signal and associated odd samples of the final digital output signal. Using the adaptive coefficients, the even and odd adaptive filters are able to independently compensate for analog variations in the two paths. Fixed, slowly varying, and clock rate variations may all be tracked out using the methods and apparatus of the present invention.
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