A successive approximation adc circuit and analog-to-digital conversion method

Abstract

The invention relates to the field of integrated circuit design, in particular to a successive approximation ADC circuit to solve the problem of low conversion precision in the traditional SAR ADC architecture in the prior art. The successive approximation ADC circuit includes: a digital-to-analog converter DAC, including a first capacitor array and a second capacitor array, both used for sampling and holding of input analog signals, and also for converting and outputting digital-to-analog signals, and a comparator for For comparing the magnitude of the two analog voltage signals output by the DAC, the successive approximation register SAR is used to control the quantized output of the analog voltage signal in the DAC cycle by cycle, and successively determine the value of each bit in the SAR according to the output result of the comparator value to obtain a digital signal and output the digital signal, the new SAR ADC circuit simplifies the complexity of circuit design, reduces the loss of silicon chip area, and improves the conversion accuracy of the successive approximation ADC.

Description

technical field [0001] The invention relates to the field of integrated circuit design, in particular to a successive approximation ADC circuit and an analog-to-digital conversion method. Background technique [0002] An analog-to-digital converter (Analog-to-Digital Converter, ADC) is mainly used to convert an analog signal into a digital signal. The currently widely used successive approximation register (Successive Approximation Registers, SAR) ADC uses a complementary metal oxide semiconductor (Complementary Metal Oxide Semiconductor, CMOS) manufacturing process, which can guarantee medium conversion accuracy (generally 8 to 16 bits) and medium conversion speed (generally below 5Msps), and has the advantages of low power consumption, small chip area, and easy implementation of multiplex conversion. [0003] refer to figure 1 As shown, the basic structure of a traditional SAR ADC includes a sample / hold circuit, a digital-to-analog converter (Digital-to-Analog Converter,...

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Problems solved by technology

[0005] Embodiments of the present invention provide a successive approximation ADC circuit and an analog-to-digital conversion method to solve the problems of high design complexity and low conversion precision in traditional SAR ADCs in the prior art

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