An Electromagnetic Interference Immune PAM-4 Transceiver System

This article presents the design of a pulse amplitude modulation (PAM-4) transceiver that supports high-speed wireline communication in the presence of electromagnetic interference (EMI). The proposed PAM-4 transceiver uses an input level shifter (ILS) and a modified electrostatic discharge (ESD)-protection circuit to reduce the effects of EMI at the transmitter. In order to overcome the effects of EMI at the receiver, the front end is designed with an enhanced input common-mode range. The transverse electromagnetic (TEM) cell method, as provided in the IEC 62132-2 standard, is followed to experimentally verify the radiated EMI-immunity of the proposed PAM-4 transceiver system over its traditional counterpart. For proof of concept, the proposed EMI-immune PAM-4 transceiver and the traditional PAM-4 transceiver circuits are implemented using the 130-nm BiCMOS process. The proposed transceiver operates at a data rate of 6.5 Gbps while maintaining an eye-opening of 70 mV for each bit in the presence of EMI, meeting the requirement of the IEEE 802.3 bs standard. The proposed PAM-4 transceiver withstands a wide range of EMI frequencies that span from 150 kHz to 2 GHz with an EMI power of 0–20 dBm.

I. Introduction

Wireline communication devices are susceptible to electromagnetic interference (EMI) generated by other integrated circuits (ICs). Previous works in [1], [2], and [3] provide detailed analyzes of postfabrication circuit failures that occur due to EMI. Traditional EMI suppression methods use EMI shields and passive filters [4], [5], [6]. However, these methods increase the bill of materials, the volume, and the total turnaround time of the product. Therefore, entirely on-chip solutions for EMI suppression are very attractive in space-constrained electronic devices despite the marginal increment that is required in the silicon area. The work in [7] proposed a simple method to model and emulate the effect of EMI, and incorporate them into the SPICE simulations to analyse the impact of the EMI on the circuits.