Successive approximation type ADC circuit and analog-to-digital conversion method

Abstract

The invention relates to the design field of the integrated circuit, and especially relates to a successive approximation type ADC circuit for solving the problem that the low conversion precision isexistent in the traditional SAR ADC architecture in the prior art. The successive approximation type ADC circuit comprises a digital-to-analog converter DAC, a comparator, and a successive approximation register SAR, wherein the DAC comprises a first capacitor array and a second capacitor array, is used for inputting sampling hold of an analog signal, and is further used for the conversion outputof a DA signal; the comparator is used for comparing two analog voltage signals output by the DAC; and the SAR is used for controlling the quantization output of the analog voltage signals in the DACcycle-by-cycle, and determining the value of each bit in the SAR one-by-one according to an output result of the comparator, thereby acquiring a digital signal and outputting the digital signal. The novel SAR ADC circuit simplifies the complexity of the circuit design, reduces the loss of a silicon wafer area, and improves the conversion precision of the successive approximation type 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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