一种基于90 nm SiGe BiCMOS工艺的4×112 Gbit/s PAM-4跨阻放大器  

A 4×112 Gbit/s PAM-4 Transimpedance Amplifier Based on 90 nm SiGe BiCMOS Process

作　　者：陈哲 CHEN Zhe(Xiamen UX High-Speed IC Co.,Ltd.,Xiamen,Fujian 361012,P.R.China;Key Laboratory for Design and Verification of Optical Communication Electrical Chip of Xiamen,Xiamen,Fujian 361012,P.R.China)

机构地区：[1]厦门优迅高速芯片有限公司,福建厦门361012 [2]厦门市光通信电芯片设计及验证重点实验室,福建厦门361012

出　　处：《微电子学》2023年第2期215-220,共6页Microelectronics

基　　金：国家工信部工业强基项目(0714-EMTC-02-00869)。

摘　　要：基于90 nm SiGe BiCMOS工艺,设计了一种高速(4×112 Gbit/s)四阶脉冲幅度调制跨阻放大器电路。为了兼顾高带宽和低噪声,采用了并联反馈架构的输入级电路。提出一种新颖的基于双吉尔伯特单元的可变增益放大器结构来适应宽动态范围的输入电流。电路利用射级退化技术来提高带宽和改善线性度。芯片测试结果表明,光接收前端链路可以实现最大74 dBΩ的跨阻增益,带宽为32 GHz,输入参考噪声电流密度为5.6 pA·Hz^(-1/2),高至3 mA的输入电流峰峰值下总谐波失真小于5%。跨阻放大器芯片进一步集成至400G QSFP-DD模块,测试结果表明,模块性能满足400G以太网FR4标准的灵敏度和传纤距离要求。A 4×112 Git/s high speed PAM-4 transimpedance amplifier was designed in a 90 nm SiGe BiCMOS IC process.A shunt-feedback input stage was used to realize high bandwidth and low noise performance.A novel double Gilbert cell based variable gain amplifier was creatively proposed to accommodate input current with a wide dynamic range.The emitter degeneration technique was used to boost the bandwidth and improve the linearity of the circuit.The chip measurement results show that the optical receiver front-end can achieve a maximum transimpedance gain of 74 dBΩ,a bandwidth of 32 GHz,an input-referred noise current density of 5.6 pA Hz^(-1/2),and a less than 5%total harmonic distortion with up to 3 mA input current.The transimpedance amplifier was further integrated into a 400G QSFP-DD optical module.The measurement results show that the module performance satisfies the sensitivity and transmission distance requirements of IEEE 400G Ethernet FR4 standard.

关 键 词：跨阻放大器 光接收机前端 四阶脉冲幅度调制 400G以太网 

分 类 号：TN433[电子电信—微电子学与固体电子学]