基于Matlab并适用于20位∑-Δ模数转换器的数字滤波器设计  

Design of digital filter based on Matlab and suitable for 20-bitΣ-ΔADC

作　　者：陈培南 李开航 CHEN Peinan;LI Kaihang(College of Physical Science&Technology,Xiamen University,Xiamen 361005,China)

机构地区：[1]厦门大学物理科学与技术学院,福建厦门361005

出　　处：《现代电子技术》2022年第22期75-80,共6页Modern Electronics Technique

摘　　要：为了满足精密仪器在称重上的高精度需求场景,文中利用Matlab/Simulink的集成工具箱对满足20位精度设计要求∑-ΔADC的数字滤波器进行行为级设计,并通过创新性的方法在Simulink中使用基本的门电路模块手动搭建起整体结构。与常规的用硬件描述语言编写整体结构相比,所搭建的结构在灵活性和底层设计上有明显的优势,对整体面积和功耗损耗的把控更加到位。设计过程中利用滤波器的特殊结构,用数学手段将其等效成一个在物理实现上可以极大简化的模型;再经过多次仿真比较,对滤波器中的量化系数进行字长量化,在满足设计要求的同时尽可能减少器件消耗。由于在数字运算中,乘法运算会显著增加器件数使用,因此使用CSD编码的方法将数字滤波器整体结构中的乘法运算降到最低,并通过移位相加的方式实现乘法运算。运用文中方法设计出的适用于称重器的20位精度数字滤波器,较传统的设计方式有明显的优势。In order to meet the high precision demand of precision instruments in weighing,the integrated toolbox of Matlab/Simulink is used to conduct behavior level design for the digital filter ofΣ-ΔADC(analog to digital converter)that can meet the 20-bit precision design requirements,and the basic gate circuit module is used to manually build the overall structure in Simulink by means of the innovative method.In comparison with the overall structure written with hardware description language,the built structure has obvious advantages in flexibility and underlying design,and has better control over the overall area and power consumption.In the design process,the special structure of the filter is used,and it is mathematically equivalent to a model that can be greatly simplified in physical implementation.After many times of simulation and comparison,word length quantization is conducted for the quantization coefficients in the filter to reduce the device consumption as much as possible while meeting the design requirements.Because multiplication operation will significantly increase the application of devices used in digital operation,CSD coding method is used to minimize the multiplication operation in the overall structure of digital filter,and the multiplication operation is realized in the mode of the shift addition.The 20-bit precision digital filter designed with the method in this paper and suitable for weighting device has obvious advantages over the filter designed with the traditional design method.

关 键 词：数字滤波器 ∑-ΔADC 模型简化 门级设计 功耗控制 仿真比较 

分 类 号：TN713[电子电信—电路与系统]