用于调制频率合成器的5bit 4阶误差反馈ΔΣ调制器设计  

Design of 5-Bit Fourth-Order ΔΣ Modulator with Error Feedback for Modulated Frequency Synthesizer Application

作　　者：张海清[1] 李文宏[1] 林蔚然[1] 曾晓洋[1] 章倩苓[1] 

机构地区：[1]复旦大学专用集成电路与系统国家重点实验室,上海200433

出　　处：《Journal of Semiconductors》2003年第11期1200-1205,共6页半导体学报（英文版）

摘　　要：针对频率合成器的高速数据调制应用 ,采用误差反馈结构 ,设计了一个用于直接 ΔΣ调制频率合成器的 5 bit4阶 ΔΣ调制器 .该结构能简化多 bit量化器的设计 ,不会对调制输入信号产生采样延迟 .通过在传递函数中引入两个极点 ,获得了比多环路级联结构更好的系统噪声性能 .在电路实现上 ,采用 CSD方法实现滤波器的系数相乘 ,并通过对系数共同项的优化 ,减少了系统的硬件消耗和功耗 。A 5bit fourth order ΔΣ modulator is designed for the application of high speed data direct ΔΣ modulation of frequency synthesizer.A new structure--error feedback structure is adopted to facilitate the design of the multi bit quantizer.This structure also has an advantage that there is no sampling delay introduced into the input signal,which is very useful for this application.By adding two poles into the transfer function,better noise performances compared with that of the MASH structure are achieved.CSD method is used for the implementation of the multiplication of coefficients of digital filter.Adoption of this method and its common sub expression sharing give an important reduction of hardware and power dissipation.Good system performance is obtained.

关 键 词：误差反馈 多bit量化 △∑调制器 CSD 频率合成器 

分 类 号：TN76[电子电信—电路与系统]