Digital weight average algorithm applied to successive approximation register analog-to-digital converter

Abstract

The present invention discloses a digital weight average algorithm applied to a successive approximation register analog-to-digital converter, characterized in that a pseudo-random number generator is added in a circuit of the successive approximation register analog-to-digital converter, a random pin code is generated by the pseudo-random number generator before each quantization of the successive approximation register analog-to-digital converter, and the connection of each unit capacitor is determined by the pin code through successive approximation register control logic, so that the unit capacitors form capacitors of different weights at random. In the present invention, the DWA algorithm is applied to a structure of the SAR ADC, so that the harmonic of an output signal is suppressed to the noise floor, to realize the first-order shaping of the noise of the output signal, thereby increasing the spurious-free dynamic range of the SAR ADC; and when the number of times of quantification of the SAR ADC reaches a certain number, the DWA algorithm enables capacitor mismatch to be allocated to each quantization, to average the capacitor mismatch, reduce the effect of the capacitor mismatch on the static characteristic and the dynamic characteristic of the SAR ADC, and improve the quantization accuracy of the SAR ADC.

Description

technical field [0001] The invention belongs to the technical fields of wireless communication, biomedicine and industrial imaging, and in particular relates to a data weight average algorithm (Digital Weight Average Algorithm, DWA algorithm) applied to a successive approximation analog-to-digital converter. Background technique [0002] Successive approximation analog-to-digital converter (SAR ADC) has the advantages of simple structure, low power consumption, and small area. SAR ADC is widely used in wireless communication, biomedical and industrial imaging and other fields. With the development of application requirements and science and technology, people put forward higher and higher requirements for the conversion accuracy of SAR ADC. However, the non-linear error caused by the capacitance mismatch in the SAR ADC capacitor array becomes the main factor limiting the higher accuracy of the SAR ADC. In the standard process, the effective number of bits that can be achiev...

AI Technical Summary

Problems solved by technology

[0003] Using existing technologies such as laser trimming technology or special processes to improve the accuracy of SARADC is complex and costly

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