PAM4: Pulse Amplitude Modulation Explained


Pulse amplitude modulation (PAM) is already a widely adopted technology in high-speed digital communications. But to understand why it has become ubiquitous in serial data standards, you first must understand the market forces driving the data networking industry. In this article, I will explore PAM4 in-depth, from its benefits and potential tradeoffs to why it was an essential innovation that ... » read more

Optimization Of The Interface Between The PD And The AFE In High-Speed, High-Density Optical Receivers


A technical paper titled “Optimizing the Photodetector/Analog Front-End Interface in Optical Communication Receivers” was published by researchers at University of Toronto. Abstract: "This article addresses the optimization of the interface between the photodetector (PD) and the analog front-end in high-speed, high-density optical communication receivers. Specifically, the article focuses... » read more

Meeting The Demands Of PAM4 Systems At 56Gbps And Beyond


According to an IDC white paper sponsored by Seagate the global datasphere will grow from 33 zettabytes (one zettabye = one trillion gigabytes) in 2018 to 175 zettabytes by 2025. This white paper also reports that today, more than 5 billion consumers interact with data every day. By 2025, that number will be 6 billion, or 75 percent of the world’s population. Figure 1 depicts this exponential... » read more

The Basics of Amplitude Modulation


Modulation is the process of varying a higher frequency carrier wave to transmit information. Though it is theoretically possible to transmit baseband signals (or information) without modulating it, it is far more efficient to send data by modulating it onto a higher frequency "carrier wave." Higher frequency waves require smaller antennas, use the available bandwidth more efficiently, and are ... » read more

M2M’s Network Impact


Synopsys’ Manmeet Walia talks examines the impact of machine-to-machine traffic and why that requires some fundamental changes in networking architectures. Two key issues that need to be addressed are scalability and latency, which require new networking architectures. https://youtu.be/2RIQt3QVPtE » read more

SerDes Signal Integrity Challenges At 28Gbps And Beyond


After nearly fifty years, NRZ technology continues to pose significant challenges as data rates approach 56Gbps and refreshed standards mandate increased receiver sensitivity (down to 35 mV). With shorter unit intervals and closing eyes, triggering becomes ever more complex and requires enhanced receiver equalization such as continuous-time-linear equalization and decision feedback equalization... » read more