Design Of Time Interleaved ADC Based On Random Channel Technology

With the rapid development of 5G technology,radar technology,and high-speed information exchange technology,high-speed analog-to-digital converters(ADCs)are becoming more and more important in order to meet the increasingly high speed requirements of the military,industrial,and civilian fields.Although the traditional ultrahigh-speed ADC structure-time interleaved ADC(TI ADC)structure can achieve extremely high sampling rates,its accuracy is often not high due to the impact of mismatch.Though researchers have proposed various correction methods for the mismatch of TI ADCs,it is still difficult to achieve ideal results in the correction of TI ADCs in practical applications.Therefore,in addition to correction methods,TI ADCs must also add random channel technology optimization methods to further optimize and improve its performance.Based on the random channel TI ADC,this paper makes a detailed analysis of its principle and implementation scheme.The main work is as follows:1.Introduction to ADC related theories.The concept of ADC and the basic structure of single-channel ADC are introduced.The principle of TI ADC is explained in detail,the single-channel ADC type suitable for random-channel TI ADC is analyzed,and the mismatch types existing in TI SAR ADC including their impact on the dynamic performance of TI ADC are listed.2.The concept and realization of channel randomization.The concept and principle of random channel are introduced in detail,and the optimization effect of random channel count on TI SAR ADC mismatch is analyzed through MATLAB modeling.The algorithm and implementation steps of channel randomization are described,including the method of switching random channels,the method of receiving data after channel randomization,and the method of generating random numbers.And combined with channel prediction algorithm to achieve task scheduling random channel TI SAR ADC.3.Analysis and modeling of the correction algorithm of the random channel TI SAR ADC.The SAR ADC digital correction algorithm based on the reference channel is discussed,the implementation process of the specific algorithm is given,and the correction effect of the algorithm is verified by MATLAB.Aiming at the characteristics of the random cahnnel TI SAR ADC,based on the original reference channel algorithm,a mismatch correction algorithm suitable for the random channel TI SAR ADC is given.It can correct the offset mismatch,capacitance mismatch and sampling time mismatch.After calibration,the reference channel is used to realize channel randomization,and further optimize the dynamic performance of TI SAR ADC.4.Circuit realization and simulation.Based on the 28 nm process,a 500 MHz randomized TI SAR ADC with 1V power supply voltage,4 working channels and 1redundant channel was realized,and the single-channle pre-simulation and the digitalanalog mixed simulation of the random channel were carried out.The layout of the single channel was drawn and post-simulation was performed.