Research On Key Technologies Of High-precision ADC

In the past ten years,the domestic industry has been upgraded on a large scale,and it has gradually transitioned to high-end manufacturing.The advent of the Sino-US trade war has broken this situation.Domestic high-end chips have been limited in production technology and process for a long time.The domestic chip industry urgently needs to be self-reliant and break through related design and manufacturing problems.Highperformance integrated circuits include digital,analog,and radio frequency.The highprecision digital-to-analog problem between digital and analog is difficult,and the mature paradigm is limited,which requires more artificial design and compromise.The analog problems of high-precision systems always focus on noise and distortion,and the pursuit of speed and accuracy? the digital problems of high-precision systems focus on reliability and timing,and pursue small area and low power consumption.At present,the linearity and noise of high-precision ADCs are approaching the limit of analog technology,and digital solutions to linearity and accuracy problems have also become a key means.The research on key technologies related to high-precision ADCs is of great significance,helping high-end manufacturing industries to get rid of their dependence on foreign countries.Take the initiative in the trade war.This thesis starts from three high-precision ADC solutions with an INL of 1ppm,analyzes the mystery of their realization of highprecision,and studies their limiting factors.In the analog aspect,the factors limiting ADC accuracy are introduced from the perspective of linearity and noise,and the solutions to these problems are studied? in the digital aspect,the reliability and timing of asynchronous SAR logic are studied,and high-reliability logic and timing systems are proposed for the pain points.Based on the study and summary of the key technologies of high-precision ADC,it is found that high-precision Pipe ADC can achieve high performance after using background correction technology,because thermal noise is difficult to break through,and there are signs of further high speed,which is the key technology research of highprecision ADC in this thesis the key of.In order to verify the key technologies of various high-precision ADCs,this thesis builds a high-speed and high-precision Pipe-SAR ADC with 16-bit 50MS/s split background correction.As an experimental platform,this design has a very large functional margin.Designed for comparators,DACs and flexible logic functions.The linearity problem of high-precision ADC has been optimized from the perspectives of sampling circuit,flip method,background correction,etc.,and achieved remarkable results.The low-frequency linearity reaches an INL of plus or minus0.5LSB,and the high-frequency of 19.3M also achieves 15.6bits ENOB and 105 d Bc The SFDR meets the linearity requirement of 16-bit 50MS/s.The performance of this design decreases after adding noise,the noise floor begins to dominate,and the harmonics and spurs are submerged.The high and low frequency performance is consistent,with ENOB of 13.5bits and SFDR of 97 d Bc,visible noise has a significant impact,this is the next step direction of efforts.