2.5Gb/s低噪声差分交叉耦合跨阻放大器的设计与实现  

A Novel 2.5 Gb/s Low Noise Differential Cross-Coupled Transimpedance Amplifier

作　　者：谢生[1] 高谦[1] 毛陆虹[1] 吴思聪[1] 谷由之 

机构地区：[1]天津大学微电子学院,天津300072

出　　处：《天津大学学报（自然科学与工程技术版）》2017年第6期656-660,共5页Journal of Tianjin University：Science and Technology

基　　金：国家自然科学基金资助项目(61474081)~~

摘　　要：本文基于UMC 0.18 μm CMOS工艺,设计了一款低噪声交叉耦合结构的跨阻放大器.该电路由优化的调节型共源共栅(RGC)结构和输出缓冲级构成,其中采用两级共源放大器作为RGC结构的辅助放大器,用于提升电路的等效跨导和带宽.此外,通过优化电路参数以及在输入端引入阶梯型无源匹配网络来进一步拓展带宽和降低电路噪声.测试结果表明,在探测器等效电容为300pF时,所设计跨阻放大器芯片的-3d B带宽为2.2GHz,跨阻增益为61.8d B?,平均等效输入噪声电流谱密度仅为9 pA/(Hz)^(1/2),成功实现了2.5Gb/s的传输速率.在1.8V电源电压下,芯片功耗为43m W,包括焊盘在内的芯片总面积为1×1mm^2.A low noise differential cross-coupled transimpedance amplifier（TIA）was designed and implemented in UMC 0.18,μm CMOS process,and the TIA consisted of a modified regulated cascode（RGC）configuration and anoutput buffer. An auxiliary amplifier constructed by two-stage common-source topology in RGC was adopted to im-prove the equivalent transconductance and the bandwidth. In addition,by optimizing the circuit parameters and in-troducing a ladder passive matching network at the input node,the bandwidth was further expanded and the noisewas also reduced. The measured results demonstrate that the fabricated TIA with a photodetector capacitance of300,pF has a transimpedance gain of 61.8,dB？ and a -3,dB bandwidth of 2.2,GHz,and the average input-referred noise current spectral density is only 9pA/Hz . The eye pattern measurement shows that a data rate of 2.5,Gb/s is successfully achieved. The chip consumes 43,mW DC power under 1.8,V supply voltage and occupies an area of 1×1,mm2 including pads.

关 键 词：光接收机 调节型共源共栅 跨阻放大器 低噪声 CMOS 

分 类 号：TN432[电子电信—微电子学与固体电子学]