Designers periodically ask us for a “general bandwidth performance rating” to compare two or more interconnect systems. Of course numerous variables affect the signal integrity performance of an interconnect, so a one-size-fits-all approximation definitely does not fit all.
Now, a new approach allows system signal integrity engineers to compare relative performance of connectors and cable assemblies while factoring in noise contributions from and interactions with other parts of the channel. It also permits the consideration of digital signal conditioning.
Samtec’s Channel Performance Metric (CPM) is a fast and efficient means to assign a single figure of merit to an interconnect. CPM evaluates the performance of a connector in a pre-defined channel. In board-to-board applications, for example, this channel consists of a transmitter, transmitter package, transmitter side PCB, connector, receiver side of PCB, receiver package and receiver.
This real-world approach factors in all impairments, such as the crosstalk and reflections, inherent in a complete channel. Samtec’s CPM is calculated by first summing all of the noise sources within the defined channel and then determining the resultant signal to noise ratio.
Through Samtec’s use of a common set of channel assumptions, relative comparison can then be made across the entire Samtec offering, which is practical and realizable. It is important to note, as CPM is a function of the necessary channel assumptions made, that CPM can and will vary from a customer-specific application.
CPM reports connector capability that is more representative of actual performance in a system, replacing our connector only data of the past.
If you want to learn more, click here to see our white paper “Introducing Channel Performance Metric: A New Definition of Interconnect Signal Integrity Performance.”
For more information, contact SIG@samtec.com.
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