Items Tagged with 'COM'

ARTICLES

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How Interconnects Work: Crosstalk Quantification

Crosstalk problems here to stay as long as interconnects are designed as the open waveguiding systems. Thus, understanding and proper quantification of the crosstalk and mitigation of the consequences are important. This article outlines multiple possible ways to quantify the crosstalk: coupling coefficients, frequency domain metrics, time-domain analysis of crosstalk, and a modern statistical approach. 


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Reflections on the Origins of COM

Channel operating margin (COM) is a well-documented IEEE standard that has been used successfully since 2014 in the design of channels and specification of interconnect. In this article, Rich Mellitz reflects on the COM origin story and considers the future of the standard.


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112 G for Quickest Data Transfer

Data usage is increasing every year, and the communications industry is working diligently to support the increased demand. This article discusses why we need more data, what data center physical layer architecture changes are needed to support higher data rates, and how connector manufacturers are improving designs to support higher data rate systems.


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BER- and COM-Way of Channel-Compliance Evaluation: What are the Sources of Differences?

We analyze the computational procedure specified for Channel Operation Margin (COM) and compare it to traditional statistical eye/BER analysis. There are a number of differences between the two approaches, ranging from how they perform channel characterization, to how they consider Tx and Rx noise and apply termination, to the differences between numerical procedures employed to convert given jitter and crosstalk responses into the vertical distribution characterizing eye diagrams and BER. We show that depending on the channel COM may potentially overestimate the effect of crosstalk and, depending on a number of factors, over- or underestimate the effect of transmit jitter, especially when the channel operates at the rate limits. We propose a modification to the COM procedure that eliminates these problems without considerable work increase.


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