Multiple-channel analog-digital converter

Abstract

The invention provides a multiple-channel analog-digital converter at least comprising a first channel branch analog-digital converter, a second channel branch analog-digital converter and a digital background calibration circuit, wherein the digital background calibration circuit comprises an interpolation filter and a minimum root-mean-square self-adaptive filter of finite-impulse-response. The interpolation filter connected with the first channel branch analog-digital converter can output a desired signal of the second channel branch analog-digital converter according to the analog-digital conversion result output from the first channel branch analog-digital converter; and the minimum root-mean-square self-adaptive filter of the finite-impulse-response, connected with the interpolation filter, can calibrate the analog-digital conversion result output from the second channel branch analog-digital converter according to the desired signal. In the multiple-channel analog-digital converter, the analog-digital conversion results output from other channel branch analog-digital converters can be calibrated by the desired signal output from the interpolation filter in the digital background calibration circuit, therefore the effects of simultaneously eliminating gain mismatching error and sampling time error are achieved and the resolution ratio of the multiple-channel analog-digital converter is improved.

Description

technical field [0001] The invention relates to an analog-to-digital converter, in particular to a multi-channel analog-to-digital converter. Background technique [0002] With the continuous development of technology, people's demand for high-speed, high-resolution analog-to-digital converters is becoming more and more urgent. The analog-to-digital converter begins to use multi-channel sub-analog-to-digital converters to perform analog-to-digital conversion on the original analog signal in different time periods, thereby increasing the conversion speed of the analog-to-digital converter. Such as figure 1 A kind of M (M is an integer not less than 2) channel analog-to-digital converter shown, it mainly includes a clock control unit, M channel sub-analog-to-digital converters and a data selector, its working principle is: when the clock At the M×kth moment (k is an integer), the first channel sub-analog-to-digital converter performs analog-to-digital conversion on the analo...

AI Technical Summary

Problems solved by technology

From (2) and (3), it is found that the non-ideal factors of gain mismatch and sampling time error lead to a spur appearing on the difference between the sampling frequency and the input frequency, which seriously affects the operation of the analog-to-digital converter precision

And traditional multi-channel analog-to-digital converters have not calibrated the sampling time error

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