Streamline analog-to-digital converter and streamline analog-to-digital converting method based on sampling capacitor randomization

Abstract

The invention provides a streamline analog-to-digital converter and a streamline analog-to-digital converting method based on sampling capacitor randomization. A sampling capacitor is marked to different working states through a sampling capacitor selector. Furthermore before a sampling phase, random selection of a group is performed on the capacitors which are not in working currently as the sampling capacitors for the phase in next sampling so that sampling holding and margin signal amplification of each streamline structure unit are synchronously performed, thereby realizing coarse quantification and margin amplification output on an input signal by an n-th grade streamline structure unit. According to the streamline analog-to-digital converter and the streamline analog-to-digital converting method, each streamline structure unit performs coarse quantification and margin amplification output on the input signal. The capacitors which are used at a sampling phase and an amplification phase for one sampling point by each streamline are in the same capacitor set; but the capacitors for performing a sampling process and an amplification process on different sampling points at the same time are independent from one another. The streamline analog-to-digital converter and the streamline analog-to-digital converting method realize independent and synchronous execution of a sampling keeping process and a margin signal amplification process of each streamline, and furthermore greatly improve conversion speed of the analog-to-digital converter.

Description

technical field [0001] The invention relates to the field of integrated circuits, in particular to a pipelined analog-to-digital converter based on sampling capacitance randomization and a conversion method. Background technique [0002] An analog-to-digital converter is an A / D converter, or ADC for short, and refers to an electronic component that converts an analog signal into a digital signal. A common analog-to-digital converter converts an input voltage signal into an output digital signal. In signal processing systems such as communication systems and radar systems, analog-to-digital converters have become an indispensable part. Commonly used analog-to-digital converter structures include low-to-medium-precision ultra-high-speed Flash (Flash) and folding-interpolating (Folding-Interpolating) structures; high-precision, medium-to-low-speed Σ-Δ and successive approximation (SAR) structures. The analog-to-digital converter structure in the above technologies mainly focu...

AI Technical Summary

Problems solved by technology

[0003] However, the input signal sampling capacitor of the traditional pipeline ADC is time-division multiplexed as the Sub DAC capacitor in the residual amplifier circuit (MDAC), which causes the sampling process of the ADCs at all levels to be different from the residual signal. The clock in the amplification and establishment process must meet the phase mutual exclusion requirements, that is, when the sampling phase is performed, the residual amplification circuit stops working; when the residual amplification phase is used, the sampling network stops working, which severely limits the conversion efficiency of the pipeline analog-to-digital converter; the traditional multi-channel time division Interleaved operational amplifiers share the pipeline analog-to-digital converter and are limited by the influence of channel mismatch such as sampling clock jitter and gain error, which severely limits the improvement of its linearity. Therefore, a new technical means is urgently needed to overcome the above technical problems

Images