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

Abstract

The invention proposes a continuous oversampling analog-to-digital converter and a digital calibration method for dynamic errors therein. This calibration method belongs to the foreground calibration. First set the analog input of the analog-to-digital converter to zero in the dynamic error detection mode, connect an additional calibration DAC unit group, and add a fixed digital signal at the same time to measure and calculate the feedback in the analog-to-digital converter. The dynamic error of the digital-to-analog converter, and the dynamic error is output and saved in digital form; then the additional calibration DAC unit group is disconnected in the dynamic error elimination mode, the analog-to-digital converter is normally connected to the analog input, and the converted digital output The calibrated digital output without dynamic error can be obtained by subtracting the dynamic error saved in the dynamic error detection mode. The invention can effectively eliminate the dynamic error of the over-sampling analog-to-digital converter by increasing simple hardware cost and operation, greatly improving its performance, and is suitable for continuous over-sampling analog-to-digital converters with various performance indicators.

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. ...

AI Technical Summary

Problems solved by technology

The disadvantage is that the calibration of the simulation will change with factors such as process angle, temperature, voltage, etc., and frequent calibration is required to ensure accuracy

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