A 12-28 Gb/s Temperature Compensated PAM-4 Transmitter with 7B4Q Maximum Transition Avoidance and Fractional-Spaced FFE

This paper presents a pulse amplitude modulation 4-level (PAM-4) transmitter with wide eye-opening performance in the temperature range from -20 to 100 ° C. The maximum transition avoidance (MTA) encoder can reduce power consumption and gate count based on the proposed 7B4Q MTA algorithm. Fractional-spaced feed-forward equalizer (FFE) compensates channel loss for 12 to 28 Gb/s. The proposed transmitter increases average eye width by 66.7% and improves level separation mismatch ratio (RLM) from 0.915 to 0.966. This work is designed using 65 nm process.