One of Samtec’s many live product demonstrations at OFC 2022 shows high-performance copper and optical cable assemblies performing equally well, whether in immersion cooling or in typical convection environments.
Ralph Page, Systems Architect at Samtec, explains the setup and results of this incredibly popular demo.
The demo consists of two identical Samtec product demonstration boards. They both incorporate a variety of high-speed interconnect systems, including copper-based Samtec Flyover® cable systems, and Firefly™ optical transceiver assemblies.
Each of these two identical demonstration boards has a Credo mixed-signal 56 Gbps PAM4 Bald Eagle 2 SERDES, generating 32 bi-directional channels of QPRBS-31 signal data.
We analyzed the performance of the two cable systems on each board, whether immersion-cooled or convection.
The first cable assembly is a mid-board to back panel design. Signals travel from the Credo chip, through about 3” of PCB trace to a NovaRay® extreme density array connector, through 12” of 34 AWG Eye Speed® twinax cable, to an ExaMAX® backplane cable connector, through one meter of 28 AWG Eye Speed twinax, and then it loops back through another 12” of 34 AWG twinax, back to the NovaRay connector on the board, and back to the chip.
The total signal path is about 1.7 meters.
The second cable on each board is a Samtec FireFly, x4, bi-directional optical transceiver cable, operating at 28 Gbps NRZ. The signal goes through an MTP loopback and returns to the Credo SERDES. This is a mid-board to front panel configuration.
Again, we have two identical boards, one in a convection environment, and the other immersed in Electrocool EC-130 dielectric coolant, from Engineered Fluids. But when we look at their performance, we see they are practically identical.
We see zero errors on both the copper twinax and optical cable assemblies, and this is pre-FEC. Of course, we also see wide-open eye patterns.
The copper cable system shows Samtec Flyover connectors functioning in a mid-board to back panel configuration, and the Firefly optical cable demonstrates mid-board to the front panel.
Here are a few other thermal management blogs that might interest you:
- A Performance Comparison of Air-Cooled vs. Immersion-Cooled Connector Systems
- Samtec and Submer Take On Immersion Cooling At OCP
- Hot Stuff! An Intro To Thermal Management
If you have questions about this demo, please email us at SIG@samtec.com
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