Successive approximation register type analog-to-digital converter and signal conversion method thereof

Abstract

The invention discloses a successive approximation register type analog-to-digital converter and a conversion method thereof. The successive approximation register type analog-to-digital converter comprises a negative capacitor array, a positive capacitor array, a comparator, a successive approximation register type logic controller and a digital decoding circuit, wherein the negative input end ofthe comparator is connected with the negative capacitor array, the positive input end of the comparator is connected with the positive capacitor array, and the successive approximation register typelogic controller is connected with the output end of the comparator and the digital decoding circuit. Decision errors generated in early steps can be effectively suppressed by using a redundant structure. Compared with a traditional structure based on a binary search algorithm, the most important difference is that the sum of the weights of low-order capacitor banks of the redundant structure is higher than the weights of the adjacent capacitor banks. By redistributing the capacitors in the negative capacitor array and the positive capacitor array and inserting a new capacitor bank, the weightcorresponding to the high-order capacitor bank is less than the sum of the weights of the low-order capacitor banks, and a redundant structure is achieved. The number of the used capacitors can be reduced by adopting a segmented structure for the capacitor array, and the power consumption is reduced.

Description

technical field [0001] The present application relates to the technical field of integrated circuits, in particular to a successive approximation register type analog-to-digital converter and a signal conversion method thereof. 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. [0003] However, when the existing successive approximation analog-to-digital converter makes a judgment (when making a decision), the decision error generated in the early step will be propagated to the subsequent step, resulting in performance degradation. [0004] To sum up, it is necessary to provide a digital-to...

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Problems solved by technology

[0003] However, when the existing successive-approximation analog-to-digital converter judges (when making a decision), the decision error generated by the early step will be propagated to the subsequent steps, resulting in performance degradation

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