A new high speed cable system, which enables 112 Gbps PAM4 signaling, can be used in mid-board, mid-board-to-front-panel, and panel-to-panel applications.
This video from DesignCon 2021 shows a live product demonstration with a Samtec NovaRay®, Flyover® Cable system operating at 112 Gbps PAM4, as well as a Bulls Eye® high-performance test cable system.
It’s all driven by a Xilinx ® Versal™ Premium GTM transceiver. The Versal Premium ACAP allows vendors to position their network systems for 800 G and beyond.
Signal Path
Ralph Page, Systems Architect at Samtec, walks us through the signal path. The Xilinx GTM transceiver generates two lanes of 31-bit, PRBS data at 112 Gbps PAM4 data rates.
Signals travel from the Xilinx ACAP through about 2” of trace in the Isola Itera MT40 test board, to a Samtec Bulls Eye connector. This Bulls Eye connector, the BE70A series, is a high-performance test system.
The signal travels from the BE70A, through 12” of low-loss microwave cable, and is terminated to Samtec precision 1.85 compression mount jacks. These 1.85 mm compression mount jack are mounted on a Samtec SI Evaluation board.
The SI Evaluation board fans the signal out through a 2” trace to the solder ball termination of a Samtec NovaRay connector and high speed cable assembly. These are the NVAM-C and NVAC series, respectively.
Signals then route through one meter of 34 AWG Eye Speed® ultra-low skew twinax cable to a second NovaRay evaluation board, to end 2 of the NovaRay cable system. The signal exits that board through more 1.85 mm compression jacks, back to the Bulls Eye test point connector, and back to the Xilinx Versal ACAP.
Results
The bit error rate “is amazing;” e-8, no FEC. The total insertion loss, di-to-die, is -40 dB at 28 GHz.
The one meter long Samtec NovaRay cable assembly accounts for less than -12 dB.
The total signal path length equals 72,” or 1.8 meters, with six interconnect transitions.
NovaRay systems combine extreme density and extreme performance, which is obviously critical as system sizes decrease while speeds increase.
If you have questions about this demonstration, contact us at SIG@samtec.com.
Samtec had several 112 Gbps PAM4 demos at DesignCon 21. Besides and this demo, here’s another, and here’s another, and here’s a PCIe Gen 6 live demonstration.
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