High-precision analog to digital conversion method and device based on double-path combination analog to digital converter

Abstract

The invention discloses a high-precision analog to digital conversion method and device based on a double-path combination analog to digital converter. The method includes the following steps that an original digital signal is separated into a precision loss part signal and a precision retention part signal, the precision loss part signal is amplified by appointed times and then transmitted to a low channel of the double-path combination analog to digital converter, and the precision retention part signal is output to a high channel of the double-path combination analog to digital converter; a preset threshold value is larger than the resolution ratio of the double-path combination analogy to digital converter; an analog signal output by the low channel of the double-path combination digital-analog converter is shrunk by appointed times, then summation is performed on an analog signal output by the high channel of the double-path analog to digital, and then the analog signal is output; the device comprises a signal separating unit, an amplifying unit, the double-path analog to digital to digital converter and a weighting and summing circuit. The high-precision digital-analog conversion method and device have the advantages of being in conversion precision, easy to achieve, reliable in conversion, low in implementation cost and low in requirement for the digital-to-analog converter.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to a high-precision digital-to-analog conversion method and device based on a dual-channel combined digital-to-analog converter. Background technique [0002] The microcomputer can only operate and process the information expressed in the form of binary numbers, and the result of the operation and processing is also this kind of digital quantity. In the servo control system, since the control signals required by various executive components are generally analog voltages and currents, the results of digital computer operations and processing usually cannot directly control the executive components, but need to be converted into analog quantities first. In order to realize the control of the controlled object through the execution components, this conversion process is called digital-to-analog conversion (Digital to Analog), and the conversion accuracy of digital-to-analog convers...

AI Technical Summary

Problems solved by technology

In order to improve the accuracy of digital-to-analog conversion, the existing technology mainly includes the following technical solutions: 1) adopt converters with high conversion digits, these converters are expensive, which is not conducive to the reduction of product cost; 2) single-chip microcomputer-based PWM-type digital-to-analog conversion technical solution, in this technical solution: PWM wave is generated by a timer, and then passes through a conversion circuit to realize an isolated digital-to-analog output. 3) The technical solution published by Chinese patent application No. 200910312137.X discloses a software and hardware implementation method for improving digital-to-analog / analog-to-digital conversion. This technical solution mainly improves the accuracy and accuracy of the reference voltage source Perform error correction processing on the converted signal to improve the conversion accuracy and reduce the cost of purchasing a precise voltage source. However, the conversion accuracy of this technical solution is still limited by the number of bits of the conversion chip, that is, the data below the resolution of the conversion chip cannot be processed. effective processing

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