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Figure 7

Sources and Compensation of Skew in Single-Ended and Differential Interconnects

VNA measurements showed that the board-to-board skew distribution of realistic board topologies/routes can be broad, and the peak measured skew was quite significant. Post processing of TDR data suggested that long routes parallel to the board edge may be particularly susceptible to skew variation due to the glass weave.
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RF Module

Ten Tips for Best Board Design Practices for IoT Applications

This design guide focuses on small form factor and low power IoT products. Even though these sorts of products are not in the same performance class as server motherboards, not paying attention to signal and power integrity design principles at the beginning of the design cycle may require multiple board spins to get your IoT product working.


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Better, Faster_Thumb_Rev

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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PCIeImage

Ensuring High Signal Quality in PCIe Gen3 Channels

The increased data rates of today’s high-speed Input/Output (I/O) buses make maintaining transmission channel signal quality all the more challenging. One reason for the challenge is the parasitic effects that result from bus interconnects. Over the past decade, data rates for electrical interconnects have experienced a dramatic increase—from 1 Gbps to 25 Gbps and beyond—to meet the ever increasing demand for more I/O bandwidth from modern networking applications and high-capacity storage.


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Stub image

Via Stubs – Are They all Bad?

We worry about via stubs in high-speed designs because they cause unwanted resonant frequency nulls which appear in the insertion loss plot (IL) of the channel. But are all via stubs bad? Well, as with most answers relating to signal integrity, “It depends.”


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