A 225mW 28Gb/s SerDes in 40nm CMOS with 13dB of analog equalization for 100GBASE-LR4 and optical transport lane 4.4 applications

A key challenge in optical networking is the development of low-power transceivers that interface to optical sub-assemblies (TOSAs & ROSAs). While SiGe technologies are often selected for jitter performance with optical links, especially on the egress path to the transmit optics, lower-power and higher levels of digital integration often result from CMOS approaches [1]. This paper describes a generic CMOS 25-to-30Gb/s SerDes for use within CDR or gearbox applications, targeting the draft requirements of the OIF 28G-VSR standard [2] and suitable for both 100GBASE-LR4/OTL4.4 gearbox and retiming applications, including CFP and CFP2 [3].