论文部分内容阅读
光纤通信在大数据时代得到广泛的应用,其速度快、带宽大、可靠性高的特点满足了对长距离、大容量信息传输的要求。前置放大器作为光接收器的前端,其性能高低直接影响到整个光接收系统的工作性能。基于SMIC 0.13μm CMOS工艺,设计完成了一款5 Gbps光接收前置放大器。首先,整体差分式结构可以消除共模噪声的干扰,降低放大器的等效输入噪声。其次,采用共源共栅的输入结构具有低输入阻抗的特点,能有效抑制光电管大电容带来的不利影响。最后,输出级采用电流模逻辑结构,解决了输出增益与带宽之间的矛盾。仿真结果表明,放大器增益达到62 d BΩ,带宽4.7 GHz;等效输入噪声30.1 p A/Hz,眼图迹线清晰,张开度较大,能够满足5 Gbps平衡光探测器通信要求。
Optical fiber communication is widely used in the era of big data, and its fast speed, large bandwidth and high reliability meet the requirements of long-distance and large-capacity information transmission. Preamplifier as a front-end optical receiver, its performance level directly affects the performance of the entire light receiving system. Based on the SMIC 0.13μm CMOS process, a 5 Gbps optical receive preamplifier was designed. First, the overall differential structure eliminates common-mode noise and reduces the amplifier’s equivalent input noise. Secondly, the cascode input structure has the characteristics of low input impedance and can effectively suppress the adverse effects caused by the large capacitance of the photocell. Finally, the output stage uses a current-mode logic structure that solves the conflict between output gain and bandwidth. The simulation results show that the gain of the amplifier reaches 62 d BΩ and the bandwidth is 4.7 GHz. The equivalent input noise is 30.1 p A / Hz. The eye traces are clear and the opening is large, which can meet the requirements of 5 Gbps balanced photodetector communication.