An adaptive digital background calibration circuit and method with adjustable down-sampling rate

Abstract

The invention relates to a self-adaptive digital background calibration circuit with adjustable down-sampling rate, comprising a sample-and-hold circuit; a first down-sampler; a low-speed high-precision reference analog-to-digital converter, which provides an accurate reference source required for calibration; a high-speed standby Calibration of the analog-to-digital converter refers to a high-speed analog-to-digital converter that needs to be processed by a calibration circuit; an adaptive digital filter; a second downsampler; a downsampling rate regulator; Subtract the data after the analog-to-digital conversion of the branch to be calibrated to complete the numerical comparison process of the branch to be calibrated and the reference branch. The invention also discloses a calibration method of an adaptive digital background calibration circuit with an adjustable downsampling rate. The present invention improves the constant down-sampling rate in the traditional digital background calibration technology to an adjustable down-sampling rate that can change continuously with the calibration process, and increases the down-sampling rate in the middle and later stages of calibration, that is, reduces the operating frequency of the digital circuit, thereby reducing the frequency of the digital circuit. power consumption.

Description

technical field [0001] The invention relates to the technical field of digital-analog hybrid integrated circuit design, in particular to an adaptive digital background calibration circuit and method with adjustable down-sampling rate. Background technique [0002] In recent years, with the reduction of process feature size, the advantages of digital circuits have become increasingly obvious. Digital background calibration technology has become the mainstream calibration technology for high-speed and high-precision analog-to-digital converters by converting the accuracy of analog circuits into the complexity of digital signal processing circuits. [0003] There is an adaptive digital background calibration technology with adjustable downsampling rate. Background technology reference document: "IEEETRANSACTIONS ON CIRCUITS AND SYSTEMS—I: REGULAR PAPERS" No. 51 "Least MeanSquare Adaptive Digital Background Calibration of Pipelined Analog-to-Digital Converters" and BackgroundAD...

AI Technical Summary

Problems solved by technology

This technology has the following disadvantages: the downsampling rate of the low-speed and high-precision reference analog-to-digital converter is fixed, and when the calibration value tends to stabilize in the later stage of calibration, a larger downsampling rate can be used to reduce the operating frequency of the digital signal processing circuit. Thereby reducing its power consumption, that is, the fixed downsampling rate makes the digital processing circuit have power consumption redundancy

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