A 15 Gb/s Non-Return-to-Zero Transmitter With 1-Tap Pre-Emphasis Feed-Forward Equalizer for Low-Power Ground Terminated Memory Interfaces

Abstract

This brief presents a 1-tap pre-emphasis transmitter (TX) for a single-ended ground-terminated memory interface with 28 nm complementary metal-oxide-semiconductor (CMOS) technology. By employing a charge pump scheme, a voltage level below ground was used to remove inter-symbol interference (ISI). Encoded with the unit interval (UI) delayed data, the proposed equalization technique increases the vertical voltage margin for the receiver (RX) compared to conventional feed-forward equalization (FFE). In addition, the short current after equalization was removed, and impedance matching for reflection was facilitated. The data rate of the proposed work is 15 Gb/s, and the data path power dissipation for the entire design is 20.3 mW. The measured energy efficiency is 1.35 pJ/bit, and the total area occupation is 0.008 mm(2).