A 32.75-Gb/s Voltage-Mode Transmitter With Three-Tap FFE in 16-nm CMOS

• Published in: IEEE journal of solid-state circuits Vol. 52; no. 10; pp. 2663 - 2678
• Main Authors: Kok Lim Chan, Kee Hian Tan, Frans, Yohan, Im, Jay, Upadhyaya, Parag, Siok Wei Lim, Roldan, Arianne, Narang, Nakul, Chin Yang Koay, Hongyuan Zhao, Ping-Chuan Chiang, Ken Chang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-10-2017; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Bit error rate; Circuits; Clocks; CMOS; Electric potential; Equalization; Field effect transistors; Impedance; Impulse response; Jitter; Resistors; source-series-termination (SST); Switches; transmitter (TX); Transmitters; Vibration; voltage-mode driver
• ISSN: 0018-9200; 1558-173X
• DOI: 10.1109/JSSC.2017.2714180

This paper describes a 32.75-Gb/s voltage-mode transmitter (TX) with three-tap feed forward equalization that is fabricated in a 16-nm FinFET CMOS technology. The TX uses a dual regulator architecture to allow independent control of output swing, output common-mode, and equalization. A hybrid impedance control scheme is presented where the total number of driver slices is used for coarse impedance control, and analog loop-based voltage control is used for fine impedance control of the TX. A finite-impulse response compensation circuit to compensate for the data dependent current due to equalization is also presented. The TX consumes 120.8 mW with 0.9- and 1.2-V supplies, provides 0.25-0.9 Vpp output swing, and achieves total jitter of 6.49 ps-pp and random jitter of 220 fs-rms at 32.75 Gb/s with bit error rate of 1e-12.