摘要
Σ-Δ调制器的结构日趋复杂,用行为级模型进行仿真对提高设计效率来说是十分必要的。首先,文章讨论了开关电容Σ-Δ调制器几种重要的非理想因素,例如时钟抖动、开关引起的非线性、开关热噪声、运放的非理想因素(等效输入噪声、有限直流增益、有限带宽、摆率和有限输出摆幅),并且相应给出了在MATLAB/SIMULINK环境下创建的行为级模型。然后,文章基于上述模型给出了一个2-1-1MASHΣ-Δ调制器行为级设计的例子。在给定过采样率为64的条件下,采样频率19.2MHz,调制器动态范围95dB,峰值信噪比94dB。
The increasing complexity of ∑-△ modulation architectures makes it necessary to use behavioral models to simulate the electrical performances for improving the efficiency. Firstly, this paper discusses some important SC ∑-△ modulation non-idealities, such as sampling jitter, switch non-linearity, switch thermal noise and operational amplifier parameters （the input referred noise, finite dc gain, finite bandwidth, slew rate and finite output swing）, and comparatively present exhaustive behavioral models in MATLAB/SIMULINK environment. Secondly, this paper presents simulation of a 2-1-1 MASH ∑-△ modulation based on the model in the behavioral level. With the over sampling ratio selected to be 64, the sampling frequency is 19.2MHz, the modulator achieves a 90dB dynamic range and a peak SNR of 95dB,
出处
《电子与封装》
2008年第8期22-27,共6页
Electronics & Packaging
