Successive approximation analog-to-digital converter and conversion method thereof

Abstract

The invention provides a successive approximation analog-to-digital converter and a conversion method thereof, and the converter comprises a sampling circuit, a conversion circuit , and a digital control circuit ; thesampling circuit is used for obtaining an in-phase end output voltage and an anti-phase end output voltage based on a current input signal during the first sampling; when sampling is not carried out for the first time, an in-phase end output voltage and an anti-phase end output voltage are obtained based on a difference value between a current input signal and a previous input signal; the conversion circuit is connected to the output end of the sampling circuit and is used for performing analog-to-digital conversion on a difference value between the in-phase end output voltage and the anti-phase end output voltage to obtain a digital signal corresponding to each sampling; and the digital control circuit is connected to the output end of the conversion circuit and is used for defining the next sampling as the first sampling if the weight bit corresponding to the current digital signal is in a set low weight bit range and the difference between the weight bit and the low weight bit is smaller than a set value during non-first sampling. Through the successive approximation type analog-to-digital converter and the conversion method thereof provided by the invention, the problem of low conversion rate of the existing SAR ADC is solved.

Description

technical field [0001] The invention belongs to the field of integrated circuit design, in particular to a successive approximation analog-to-digital converter and a conversion method thereof. Background technique [0002] The analog-to-digital converter (ADC) is a bridge between the natural world and the machine world, and it is also an indispensable component in the measurement control system. Features such as high and low latency are widely used. [0003] The conversion cycle of the SAR ADC can be divided into two stages according to the actual working time sequence: the first stage is sampling, which accurately samples the analog signal to be converted to the capacitor and holds it, and the second stage is conversion, which samples the first stage The obtained analog signal is quantized, converted into a digital signal and output; therefore, if the SAR ADC output is to meet the high-speed and high-precision requirements, a way must be found to compress the time required...

AI Technical Summary

Problems solved by technology

[0005] In view of the above-mentioned shortcoming of prior art, the object of the present invention is to provide a kind of successive approximation type analog-to-digital converter and conversion method thereof, for solving the problem of slow conversion rate of existing SAR ADC

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