5-Gb/s PAM4 Transmitter IC Using Compensation Circuit in an 180-nm CMOS

This paper proposes a 5-Gb/s four-level pulse amplitude modulation (PAM4) transmitter using compensation circuit in data transmission systems. In PAM4 systems, the signal amplitude requires smaller rising and falling times. To achieve this, we adopted an analog feed forward equalizing (FFE) for the compensation in PAM4 transmitter. To confirm the advantage of the proposed technique, we fabricated a 5-Gb/s PAM4 transmitter IC in an 180-nm CMOS process for this work. The measured rising and falling times were 18% and 13% smaller than those without FFE, respectively.