| 摘要 |
Mismatch errors within oversampled analog ti digital (ADC) and digital to analog (DAC) data converters limit the overall conversion accuracy. A circuit is provided which interchanges the analog segments within a multibit oversampled converter in a fashion to move the mismatch errors away from the overall converter's passband frequencies and towards other frequenceis where they do not interfere with the signal to be converted. The circuit works by minimising the differences in the signals which control the individual segments. Circuits may be provided for achieving first, second and higher order "shaping" of the mismatch errors. The invention also provides a circuit in which exchange of the analog elements with the DACs of multibit oversampled converters is effected using a circular queue, so moving the mismatch errors to high frequency where they do not interfere with the signal to be converted.
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