High-speed transmitter for fully differential current-mode polyquaternary signaling scheme

Abstract

In this work we propose fully differential current-mode polyquaternary signaling transmitter for high-speed data transmission over chip-to-chip interconnect. Polyquaternary signaling is a bandwidth efficient signaling scheme suitable for bandwidth constrained and crosstalk prone chip-to-chip interconnect. Basic polyquaternary precoding scheme is adopted for symbol-by-symbol transmission which requires simple detection logic without increasing the precoding complexity. To achieve high-speed operation pipelining and parallel processing are incorporated in to the system building blocks without much increase of power. Polyquaternary filter is integrated within the current-mode driver to reduce power and area. All building blocks are realized in current-mode logic(CML). The circuits are implemented in 1.8-V, 0.18-µm digital CMOS process technology. The power consumed in the transmitter is 53.32-mW at the data transmission rate of 10-Gb/s over 20-cm FR4 PCB trace for the targeted bit error rate(BER) of 10−12