https://scholar.dgist.ac.kr/handle/20.500.11750/47660 2026-04-05T01:26:46Z https://scholar.dgist.ac.kr/handle/20.500.11750/60118 Title: A Spectral-Efficient Low-Power NRZ/PAM-4 Dual-Mode Wireline Transmitter for Multidrop Interfaces Author(s): Kim, Donggeon; Gharibdoust, Kiarash; Tajalli, Armin; Lee, Kyoungtae; Kim, Gain Abstract: This paper presents a reconfigurable and energy-efficient digital spectrum shaping signaling (DSSS) for multidrop interfaces, where the output spectrum of the transmitted data is shaped using the 2-times repetitive block transmission to avoid frequency notches in the multidrop channel, thereby achieving a data rate up to 4x the first channel notch frequency. In conventional wireline transceivers (TRX), compensating for frequency notches requires a large number of decision feedback equalizer (DFE) taps at the receiver, resulting in significant area and power overhead. In contrast, the proposed DSSS architecture supports spectrum-efficient reconfigurable dual-mode NRZ/PAM4, reducing required equalization efforts and improving energy efficiency. The proposed scheme and its transmitter (TX) were first validated through event-driven behavioral simulations using XMODEL and verified with equipment-based measurements. Post-layout simulation results in 28nm CMOS process demonstrated 4 Gb/s data rate communicating over a channel having its first > 30 dB notch at 1 GHz, with a 235mV vertical eye opening and a TX energy efficiency of 0.39 pJ/b at 0.8V supply. 2025-08-07T15:00:00Z