6.7 A 112Gb/s PAM-4 Voltage-Mode Transmitter with 4-Tap Two-Step FFE and Automatic Phase Alignment Techniques in 40nm CMOS
Pen-Jui Peng, Yan-Ting Chen, Sheng-Tsung Lai, Chao‐Hsuan Chen, Hsiang-En Huang, Ted Shih · 2019
The continuous development of wireline communication encourages transmitters to operate at higher speeds. The applications of 400GbE also push the transmitter to be designed at 112Gb/s for a single lane [1-2]. However, the use of advanced processes (<;16nm) hardly reduces the costs. This paper presents a 112Gb/s PAM-4 voltage-mode transmitter fabricated in 40nm CMOS by using the proposed two-step FFE and the automatic phase alignment techniques, improving the output bandwidth as well as the power dissipation. It delivers high-quality eye diagrams under 5.5dB loss at 28GHz with 3.89pJ/b efficiency.