Signal Integrity

Demystifying Edge Launch Connectors

A particularly challenging configuration is the edge launch, where connectors are used on the edge of the PCB with a transition to a microstrip trace. A poorly optimized connector footprint leads to degradation of the signal integrity performance, especially at high data rates. This paper identifies the root cause of the problem by showing how the electromagnetic fields behave at the transition area. Then it presents a design methodology, using simulated and measured data, that ensures the quality of high-speed data transmission.


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Test System Addresses Demands of 56/112G PAM4 Using Upcoming IEEE P370 Standard

eSilicon was in the Samtec booth at DesignCon 2019 presenting their collaboration with Wild River Technology to develop an advanced test system that addresses the difficult signal integrity demands of 56/112G PAM4 operation. The test system design utilizes the upcoming IEEE P370 standard in association with compliance metrics 802.3bs, OIF CEI – 56G PAM4, and COBO to validate the required performance.


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Quick, Simple Way to Measure the System Bandwidth of a Scope-Probe System

While we get the scope’s bandwidth from the vendor, as soon as we add a cable, probe, or amplifier to the scope, we decrease the system bandwidth. The new system bandwidth is as important to know as the scope’s bandwidth, but it is generally difficult to measure except in a calibration lab. We offer a simple method of evaluating the transfer function and system bandwidth of any probing system using a wide band noise source. This method not only gives us information about the probes and interconnects, but it also tells us how the scope responds to the measurement system, information which cannot be measured by a VNA alone.


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16Gb/s and Beyond with Single-Ended I/O in High-Performance Graphics Memory

The paper discusses the development of GDDR6 as a lower-risk and more cost-effective solution as compared to other high-bandwidth memory solutions.


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A Study of Forward Error Correction Codes for SAS Channels

This paper evaluates the performance of several choices of Reed-Solomon code and shows how a frame-interleaved RS(30,26) code can achieve 1e-15 bit-error rate (BER) in the presence of burst errors. See the authors conclude that, as data rates go higher, current 128b/130b encoding is not a good option as the two-bit 01/10 overhead suffers due to its Nyquist pattern property.


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