In this video from Design 2019, Scott McMorrow walks us through a live demonstration showing how NovaRay® Cable assemblies offer extreme density while enabling 112 Gbps PAM4 performance. In combination with an ExaMAX® Backplane Cable assembly, the traditional backplane architecture is retained, but with higher performance targets and lower PCB complexity.
Samtec Flyover® systems can help extend signal reach and density to achieve next gen speeds by routing signals via Eye Speed® ultra-low skew twinax cable instead of through lossy PCBs. Eye Speed Cable typically runs four gauge sizes faster than other cables.
Samtec Flyover is commonly used in mid-board applications. Most mid-board applications place the cable assembly connector close to the chip and direct the signal to the front panel through the cable.
Samtec Flyover also allows designers to go from one board to another as a flexible backplane architecture within a rack, and it can be used as a rack-to-rack interconnect.
Backplane Cable Demo
This demonstration is a combination of the mid-board and backplane applications.
A full 112 Gbps PAM4 chip-to-chip channel routes from a Xilinx 112Gbps PAM4 Transceiver Test Chip; it generates 31 bit PRBS data at 112 Gbps PAM4. These signals travel through precision RF 2.92 mm cable assemblies to a Samtec NovaRay cable assembly system.
The signals then travel through 12” of 34 AWG Eye Speed® Ultra Low Skew Twinax Cable to an ExaMAX Backplane socket on the back panel. The backplane socket mates via a panel retention bracket to a one meter, 30 AWG ExaMAX backplane cable assembly. This cable assembly passes through a lower-cost, and less complex backplane.
The return path repeats itself – the one meter of 30 AWG ExaMAX backplane cable transfers from the socket to 12” of 34 AWG ultra-low skew twinax cable, to a NovaRay board level connector, and back to the Xilinx 112Gbps PAM4 Transceiver Test Chip which processes the data to display BER performance.
The loss for the entire signal path, including all cable assemblies and pcbs, is approximately 28dB. This demonstration has 14 different connector interfaces.
The results are impressive: the Pre-FEC (“FEC-less”) BER is 2.15e-07. In the video, Scott walks us through the results and demo set-up in greater detail.
Samtec NovaRay is an industry-leading high bandwidth, high-density interconnect system. The innovative pin-to-ground differential pair configuration enables very low crosstalk to 40 GHz+, tight impedance control, and minimal variance in data rate as stack heights increase.
The NovaRay cable assembly handles up to 4 Tbps aggregate data rate, in 9x IEEE, 400 Gbps channels.
ExaMAX high-speed backplane cable assemblies, the EBCM and EBCF series, utilize Samtec’s Eye Speed ultra-low skew twinax cable and optimized direct-attach technology for improved signal integrity, increased flexibility and routability. The cable assemblies are intermateable with all ExaMAX connectors and are highly customizable. Cables are available in 4 and 6 pairs, and 6, 8, 10, and 12 columns.
If you have questions, please contact us at SIG@samtec.com