Successive Approximation Analog-to-Digital Converter Based on Asymmetric Differential Capacitor Array

Abstract

The invention relates to a successive approximation register analog-to-digital converter based on an asymmetric differential capacitor array. The successive approximation register analog-to-digital converter comprises a sample hold circuit, a comparer and a logic control module. The sample hold circuit comprises an asymmetric differential capacitor array and a sample switch module. According to the asymmetric differential capacitor array, a first input end is selectively electrically connected with a common-mode voltage end and a grounding terminal through a single pole double throw switch, asecond input end is electrically connected with an output end of the sample switch module, a third input end is electrically connected with a first output end of the logic control module, and the output end is electrically connected with the comparer. The first input end and the second input end of the sample switch module are electrically connected with an analog signal negative input end and ananalog signal positive input end. The output end of the comparer is electrically connected with the input end of the logic control module. According to the successive approximation register analog-to-digital converter provided by the invention, the power consumption can be effectively reduced, a capacitor area can be reduced, and the design difficulty can be reduced.

Description

technical field [0001] The invention belongs to the technical field of analog-to-digital conversion, and in particular relates to a successive approximation analog-to-digital converter based on an asymmetric differential capacitance array. Background technique [0002] At present, with the promotion of wearable devices and the development of precision biological instruments, successive approximation analog-to-digital converters are widely used because of their simple structure and low power consumption. Since the successive approximation analog-to-digital converter does not require linear gain blocks such as operational amplifiers, it can better adapt to the process evolution trend of feature size reduction and power supply voltage reduction. With the advancement of technology, the conversion rate that can be achieved by successive approximation analog-to-digital converters has increased to hundreds of megabytes, which can be compared with pipeline-type analog-to-digital con...

AI Technical Summary

Problems solved by technology

For the traditional successive approximation analog-to-digital converter based on capacitor array, due to the relatively large area of ​​the capacitor array, the accuracy cannot be achieved very high, and it will cause the problem of increased power consumption

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