CMOS broadband amplifiers for optical communications and optical interconnects

This paper presents different design concepts and approaches of CMOS broadband amplifiers for optical communications and optical interconnects. The design techniques of distributed amplifier (DA), capacitive peaking, and inductor/transformer peaking are reviewed. Using the proposed inductive peaking techniques, we have demonstrated previously a 40-Gb/s transimpedance amplifier (TIA) in 0.18 μm CMOS and a broadband amplifier with a 70-GHz bandwidth in 0.13 μm CMOS. With an emphasis on low power and miniature characteristics, different TIA topologies are discussed for the emerging applications of optical interconnects. Our recent study demonstrates a TIA achieving a transimpedance gain of 54.5 dBΩ and a bandwidth of 4.3 GHz under power consumption of 11.5 mW with a chip area of only 0.0077 mm² in 0.18 μm CMOS, which permits a data transmission rate up to 7 Gb/s for optical interconnect applications.