High-Speed Twinax Cable Solutions To 224 and 112 Gbps PAM4
At DesignCon 2024, Samtec had several live product demonstrations showing a wide variety of Samtec Flyover® cable solutions, all with excellent performance at 224 and 112 Gbps PAM4 data rates. One thing they have in common is Samtec’s Eye Speed®, ultra-low skew twinax cable.
Eye Speed is Samtec’s proprietary, co-extruded twinax cable that optimizes signal integrity, bandwidth, and reach. Because of our unique manufacturing process, Samtec Eye Speed cable is ultra-low skew, meaning the performance doesn’t vary when the cable bends.
In the video above, Samtec’s Andy Shrout quickly walks us through three live product demonstrations at DesignCon 2024.
112 Gbps PAM4 While Subject To Dynamic Flexing
The first, which received a lot of attention, shows the superior performance, as well as the ruggedness, of Eye Speed twinax. And, it’s fun.
An Alphawave Alphacore SerDes delivers 112 Gbps PAM4 signals, which are then run through a long-reach cable system that is subjected to dynamic flexing. The Eye Speed cable runs through the Samtec “HDR-Cade” game, where it bends, twists, stops, starts, and receives all kinds of harsh and rugged treatment.
That’s because the cable flexing is controlled by whoever is playing the game. Despite this brutal treatment, the cable performance is great. We see a BER of e-8. Most importantly, there are no spikes. And remember, we’re taking these measurements in real-time while we’re bending the cable.
BTW, the NovaRay® I/O cable being flexed in the arcade is three meters long.
High-Speed Twinax Cable Solutions: 224 Gbps PAM4
Samtec Eye Speed twinax cable is also used in all of our 224 Gbps PAM4 DesignCon demos.
Next in the video, we see a demo that incorporates a Rohde and Schwarz ZVA 110 VNA. The VNA measures insertion loss all the way to 110 GHz, through a Samtec Si-Fly® HD cable assembly. The loss is flat until 80 GHz, and there’s no suckout. Excellent performance!
Lastly in the video, we see a live product demonstration where a Synopsys 224 G Ethernet PHY is transmitting 31-bit, PRBS data at 224 Gbps PAM4. The signal travels through the Samtec Si-Fly HD cable assembly, which incorporates 20” of Eye Speed Ultra Low Skew Twinax, then to a second Synopsys 224 G PHY for analysis.
The results are impressive, with a PRE-FEC BER of e-6. The total loss is approximately 40 dB at 56 GHz. The loss attributed to the Samtec cable assembly and two characterization boards is 29 dB. And remember, this cable assembly is over half a meter long, at 224 Gbps.
Samtec Eye Speed Twinax cable has better loss characteristics than PCB transmission lines. This is because of the dielectric material used, as well as the electrical properties of the conductor.
If you have any questions about any of the demonstrations discussed today, contact us at [email protected]
Leave a Reply