Oversampling analog-to-digital converter and dynamic error calibration method for feedback digital-to-analog converter thereof

Abstract

The invention provides a continuous oversampling analog-to-digital converter and a digital calibration method for dynamic errors in a feedback analog-to-digital converter. The calibration method belongs to front desk calibration and includes the steps: firstly, setting the analog input of the analog-to-digital converter to zero in a dynamic error detection mode, connecting an additional calibration DAC unit group, adding a fixed digital signal to measure the dynamic errors of the feedback digital-to-analog converter in the analog-to-digital converter at the same time, and outputting and savingthe dynamic errors in a digital form; then disconnecting an additional calibration DAC unit group in a dynamic error cancellation mode, normally connecting the analog-to-digital converter to analog input, and subtracting the saved dynamic errors under a dynamic error detection mode from the converted digital output, to obtain the calibrated digital output without dynamic errors. The dynamic errors of the oversampling analog-to-digital converter can be effectively eliminated, by adding simple hardware cost and operation, to greatly improve the performance thereof, and the digital calibration method for dynamic errors is suitable for the continuous oversampling analog-to-digital converters with various performance indexes.

Description

technical field [0001] The invention relates to the field of mixed signal circuits, in particular to a digital foreground calibration method for calibrating an oversampling analog-to-digital converter and feeding back the dynamic error of the digital-to-analog converter. Background technique [0002] In electronic circuits, the analog-to-digital converter (ADC) is an important module, which is responsible for converting analog signals such as sound, image and radio waves into digital signals and transmitting them to subsequent digital circuits for various signal processing. The indicators to measure the analog-to-digital converter mainly include bandwidth (speed), precision and power consumption. [0003] The oversampling analog-to-digital converter is an important structure in the analog-to-digital converter, and its basic structure is as follows: figure 1 As shown, it is composed of a loop filter 1.1, a quantizer 1.2 and a feedback DAC (digital-to-analog converter) 1.3. ...

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The disadvantage is that the calibration of the simulation will change with factors such as pro

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