A 12-Channel,30Gb/s,0.18μm CMOS Front-End Amplifier for Parallel Optic-Fiber Receivers  

12路并行30Gb/s 0.18μm CMOS光接收前端放大器(英文)

作　　者：李智群[1] 薛兆丰[1] 王志功[1] 冯军[1] 

机构地区：[1]东南大学射频与光电集成电路研究所,南京210096

出　　处：《Journal of Semiconductors》2006年第1期47-53,共7页半导体学报（英文版）

基　　金：国家高技术研究发展计划资助项目(批准号:2003AA312040)~~

摘　　要：This paper presents a 12-channel,30Gb/s front-end amplifier realized in standard 0.18μm CMOS technology for parallel optlc-fiber receivers. In order to overcome the problem of inadequate bandwidth caused by the large parasitical capacitor of CMOS photo-detectors,a regulated-cascode structure and noise optimization are used in the design of the transimpedance amplifier. The experimental results indicate that, with a parasitical capacitance of 2pF,a single channel is able to work at bite rates of up to 2.5Gb/s,and a clear eye diagram is obtained with a 0. 8mVpp input. Furthermore, an isolation structure combined with a p^＋ guard.ring （PGR）, an n^＋ guard-ring （NGR）,and a deep-n-well （DNW） for parallel amplifier is also presented. Taking this combined structure, the crosstalk and the substrate noise coupling have been effectively reduced. Compared with the isolation of PGR or PGR ＋ NGR,the measured results show that the isolation degree of this structure is improved by 29.2 and 8. ldB at 1GHz,and by 8. 1 and 2. 5dB at 2GHz,respectively. With a 1.8V supply,each channel of the front-end amplifier consumes a DC power of 85mW,and the total power consumption of 12 channels is about 1W.给出了一个采用TSMC0.18μm CMOS工艺设计并实现的12路30Gb/s并行光接收前端放大器.电路设计采用RGC结构和噪声优化技术,克服了CMOS光检测器大寄生电容造成的带宽不够的问题.测试结果表明,在2pF的寄生电容下单信道传输速率达到了2.5Gb/s,在0.8mVpp输入下得到了清晰的眼图.提出了一种同时采用p+保护环(PGR)、n+保护环(NGR)和深n阱(DNW)的并行放大器隔离结构,有效地抑制了并行放大器之间的串扰,减小了放大器之间的衬底耦合噪声.测量结果表明,这种结构与PGR和PGR+NGR相比,在1GHz时放大器之间的隔离度分别提高了29.2和8.1dB,在2GHz时放大器之间的隔离度分别提高了8.1和2.5dB.芯片采用1.8V电源供电,单路前端放大器的功耗为85mW,12路总功耗约为1W.

关 键 词：parallel optic-fiber receiver front-end amplifier regulated-cascode substrate noise coupling ISOLATION 

分 类 号：TN722[电子电信—电路与系统]