一个用于GSM的80dB动态范围Σ-Δ调制器  

An 80dB Dynamic Range Σ-Δ Modulator for a GSM System

作　　者：陈建球[1] 任俊彦[1] 许俊[1] 王照钢[1] 李怡然[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201203

出　　处：《Journal of Semiconductors》2007年第2期294-301,共8页半导体学报（英文版）

摘　　要：设计了一个用于GSM系统的Sigma-Delta调制器.GSM系统要求信号带宽大于200kHz,动态范围大于80dB.为了能取得较低的过采样率以降低功耗,采用了级联结构(MASH)来实现,与单环高阶结构相比,它具有稳定及易于实现的优点.设计工作时钟为16MHz,过采样率为32,基带带宽为250kHz,电路仿真可以达到最高82dB的SNDR和87dB的动态范围.芯片采用SMIC0.18μm工艺进行流片,面积为1.2mm×1.8mm.芯片测试效果最高SNDR=74.4dB,动态范围超过80dB,测试结果与电路仿真结果相近,达到了预定的设计目标.芯片工作在1.8V电源电压下,功耗为16.7mW.We propose a Sigma-Delta modulator for a GSM system,whose channel bandwidth is wider than 200kHz and dynamic range is more than 80dB. A multi-stage noise shaping structure,rather than a single-loop structure,is chosen to achieve lower OSR and higher stabilization. The design parameters are： fCLK=16MHz, OSR=32, and baseband width = 250kHz. Simulation at the circuit level achieves a peak SNDR of 82dB and DR of 87dB. The chip is implemented in SMIC 0. 18μm CMOS technology,and the area is 1.2mm × 1.8mm. Measurement at 16MHz clock frequency and OSR of 32 achieves a peak SNDR of 75dB and DR over 80dB,which are close to the values obtained by the circuit level simulation. The chip operates under a 1.8V power supply with a power dissipation of 16. 7mW.

关 键 词：SIGMA-DELTA调制器 过采样 级联结构 动态范围 

分 类 号：TN761[电子电信—电路与系统]