一种应用于音频的DAC中插值滤波器的设计  

A Multistage Interpolation Design of an Audio DAC

作　　者：秦坤[1] 陆铁军[1] 肖杜[1] 王宗民[1] 

机构地区：[1]北京微电子技术研究所,北京100076

出　　处：《微电子学与计算机》2009年第11期82-85,共4页Microelectronics & Computer

摘　　要：设计了一种应用于24位音频DAC中实现128倍过采样的插值滤波器,该插值滤波器采用多级插值的方法,根据前后级采样速率不同的特点,选择不同的滤波器结构.采用一种基于CSD编码的方法来实现一种多相结构,这种多相结构不需要乘法器.该方法在减小了控制系统复杂性的同时也减小了芯片的面积.仿真结果表明,该插值滤波器的通带纹波和阻带衰减都达到了设计要求.An area-efficient 128x interpolator filter used in audio digital-to-analog convert is presented in this paper. According to different sampling rate in different stage, different filter structure is employed in the multistage interpolation. A novel method based on CSD coding is proposed to realize a polyphase multiplier-free halfband subfilter with a high resolution. This approach reduces the complexity of the control system and saves chip area dramatically. The simulation result demonstrates that the ripple in the passband and the attenuation in the stop band is desirable.

关 键 词：插值滤波器 半带滤波器 CIC滤波器 补偿滤波器 CSD编码 

分 类 号：TN47[电子电信—微电子学与固体电子学]