Research On System Structure And Linearity Optimization Of Sigma Delta Modulator

Analog-to-digital converters(ADCs)can convert analog signals into digital signals,which are essential components for systems that need to collect and process analog signals.Sigma Delta ADC based on oversampling and noise shaping techniques,with its high resolution,has been widely used in audio,advanced sensors and other aspects.In recent years,Sigma Delta ADC typically achieves higher performance by optimizing the modulator system architecture or using multi-bit quantizer in terms of linearity,resolution,power consumption and area.This paper mainly studies the structure and linearity optimization of Sigma Delta modulator system.In this paper,Sigma Delta modulators based on noise coupling technique is researched and analyzed,and behavior modeling and simulation carried out by MATLAB.The structure and basic performance of modulators based on noise coupling technique are compared.And the reason of the linearity of Sigma Delta modulator based on noise coupling technique is analyzed in depth,and the simulation and verification are carried out.Nonlinearity of Multi-bit quantizer often caused poor performance of ADCs.How to ensure small areas and improve system linearity at the same time,is the key to enhance ADCs performance.In this paper,a new randomized DWA algorithm is designed,researched and simulated.Using MATLAB modeling,simulation results show that DWA algorithm can improve the performance of modulator.The DWA algorithm circuit is designed with digital VHDL code,and the correctness of the code function is verified by Modelsim.Design Compiler is used to incorporate RTL-level code into netlist.Compared with the traditional DWA algorithm,the total area of the DWA algorithm is reduced by 8% and the total dynamic power consumption 13.9%.In this paper,the linearity and resolution of the whole Sigma Delta modulator are improved,and the power and area in the system level are reduced by using noise coupling and new DWA techniques.