An Inductor-less VCSEL Driver for Short Distance Optical Interconnection

• Main Authors: Peng, Hsin-Chan, 彭新展
• Other Authors: Hsu, Yung-Jane
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/41314081208017146165

碩士 === 國立清華大學 === 電子工程研究所 === 101 === Due to the wide spread of mobile devices, the needs of short–distance information processing grow fast recently. Since the properties and the bandwidth of electrical communication are restricted by the physical characteristics of copper cables, the application of electrical communication will reach its limit in the near future. However, the optical fiber communication performs well at the high bandwidth interface and has only a few drawbacks at the electrical interface, therefore the short-distance optical fiber communication system has become an important research topic. Because of low energy consumption of short-distance optical fiber communication system, VCSEL is usually chosen as a trigger for transferring electrical energy to light. The operation bandwidth of Pre-Amplifier in VCSEL driver is usually increased by the inductor due to its simple design. However, the inductor occupies a huge portion of layout, and the coils inside easily generates electromagnetic fields while the current flowing through them. To overcome this issue, the distance between different passive inductor should be extended, which occupies more area in layout. In this thesis, active inductor is introduced to solve the problem above. This design contains negative capacitance, folded active inductor, cascode structure, and active feedback circuit etc. to increase the bandwidth but lower the power consumption. VCSEL Driver is produced by TSMC 0.18μm CMOS fabrication, and the range of current is from 5mA to 15mA. The optical measurement result shows that the power consumption of Pre-Amplifier is only 182mW, the total area of circuit is 0.48mm x 0.44mm, and Bit Rate is 7.5Gb/s.