基于MATLAB的分段式电流舵DAC建模与仿真

摘要

摘要

高速高分辨率的D/A转换器是现代通信系统的重要组成部分，而分段式电流舵结构是最佳选择之一。本文首先介绍了分段式电流舵DAC行为级理想和非理想模型。然后是通过在SIMULINK环境下构建一系列的子系统来分别实现了4+8和6+6结构的12位分段式电流舵DAC行为级理想和非理想模型。通过对理想模型的仿真验证了模型的正确性。本文中的非理想模型考虑了电流源失配和电流源输出阻抗有限大这两个主要的非理想因素。对4+8和6+6两种非理想模型的仿真结果进行了分析和比较并探究了不同程度的非理想因素对4+8和6+6两种结构的信噪比、无杂波动态范围、有效位数等性能参数的影响。非理想模型的仿真结果较好地反映了非理想因素对分段式电流舵DAC性能的影响。

关键词：分段式电流舵，DAC，静态和动态参数，行为模型，仿真

ABSTRACT

ABSTRACT

High-speed high-resolution D / A converters are important building blocks in modern communication systems. The segmented current steering structure is one of the best. This paper introduces the ideal behavioral model and the non-ideal behavioral model of the segmented current-steering DAC. Then an ideal behavioral model and non-ideal behavioral model of 12 bits current-steering DACs in 4+8 and 6+6 structure are created in the SIMULINK environment by building a series of subsystems. The validity of the ideal model has been verified by simulation.In this article, the two main non-ideal factors which are current source mismatch and the limited current source output impedance are added into non-ideal models.The simulation results of the two kinds of non-ideal models are analyzed and compared. We explored how performance parameters such as signal-to-noise ratio (SNR), Spurious-Free Dynamic Range (SFDR) and effective number of bits (ENOB) are influenced by different levels of non-ideal factors in two kinds of structures. The simulation results of non-ideal models reflect the influence of non-ideal factors on the current-steering DAC.

Keywords: segmented current steering current-steering DAC

Static and dynamic parameters behavioral model simulation