开关电容滤波器混叠效应仿真及抑制  

Aliasing effects simulation and suppress of switched capacitor filter

作　　者：陈海亮[1] 刘鑫[2,3] 任勇峰[2] 瞿林[2] 

机构地区：[1]北京航天长征飞行器研究所,北京100076 [2]中北大学电子测试技术国家重点实验室,山西太原030051 [3]太原科技大学电子信息工程学院,山西太原030024

出　　处：《电子技术应用》2014年第7期37-39,43,共4页Application of Electronic Technique

摘　　要：在模拟信号调理过程中,模拟信号的滤波电路是硬件设计的关键。普通的低阶有源滤波电路无法满足传感器信号滤波电路对衰减率的要求,高阶集成开关电容滤波芯片能够实现高精度、稳定的滤波特性,但由于开关电容滤波芯片具有采样特性,不可避免地会出现混叠现象。通过对滤波芯片混叠效应的理论分析,定量地计算出后续二阶压控低通滤波电路的截止频率。实验证明,该方法能够有效抑制开关电容滤波电路出现的混叠效应。In analog signal conditioning, the hardware design of analog signal filtering circuit is the key technology. The low order active filter circuit can not meet the requirement of attenuation rate in the sensor condition circuit. The high-order integrated switched capacitance filter chip can achieve high accuracy and stability. But because of the sampling characteristics of integrated switch-capacitor filter, there is aliasing phenomenon inevitably. By analyzing the aliasing effect on the filter circuit, quantitative calculation of cutoff frequency of postpositive second-order voltage-controlled low-pass filter is given. The experiments show that this design method can effectively suppress the aliasing effect in switch capacitor filter circuit.

关 键 词：开关电容 混叠 低通滤波 阶梯噪声 

分 类 号：TP274[自动化与计算机技术—检测技术与自动化装置]