Samtec Welcomes You to the Future with Proven 224G PAM4 Interconnect Solutions

We all know about the relentless march of Moore’s Law. Denser, faster, and cheaper semiconductor devices that fuel the innovations that surround us. For this discussion, I will lump the significant movement from single chip advances to multi-chip strategies into a single thread as devices continue to get smaller, faster and more cost and power efficient. Across the data center, the 5G wireless network and the plethora of AI applications that surround us the exponential increase in processing is easy to see. There is another aspect of this technology revolution that is just as important – the ability to transmit ever-increasing data volumes at ever-increasing speed. That is the subject of this post. Let’s explore how Samtec welcomes you to the future with proven 224G PAM4 interconnect solutions.

What is 224G PAM4 and Why Does it Matter?

The purpose of any signal modulation scheme is to transmit bytes of data over coax, fiber, or a PCB trace. There is more than one approach to signal modulation, but it turns out pulse amplitude modulation 4-level (PAM4) is the format that has become the leader. This approach uses four voltage levels to represent four combinations of two bits of logic (00, 01, 10, and 11). Because of the use of multiple voltage levels, PAM4 has twice the throughput compared to other approaches.

There is no free lunch, however. Compared to other approaches, PAM4 has a worse signal to noise ratio (SNR), more incidence of signal reflections and requires more expensive equipment to implement. So, the goal is to build signal channels that support PAM4 in a way that capitalizes on its benefits and neutralizes its weaknesses. 224 gigabit per second PAM4 channels will enable the next generation of communication protocols in data centers, 5G networks and other massive, networked device configurations.

Samtec’s Approach to New Communication Channel Performance Demands

Samtec has developed a series of next-generation interconnect solutions that deliver the flexibility and performance required for 224 Gbps PAM4 channels.  Areas such as data centers, artificial intelligence (AI), machine learning (ML), and quantum computing are all needing this capability, and Samtec’s products and associated roadmaps are designed to satisfy these high-performance needs.

Let’s look at the family of products serving this area from Samtec and how they work together to deliver a complete solution.

Si-Fly™ HD (on package or ASIC adjacent cable system)

• Industry’s highest-density on-package or ASIC-adjacent cable system
• 207 differential pairs per square inch
• Eye Speed® AIR™ hyper low skew 33 AWG twinax cable
• Samtec Flyover® Cable Technology
• Designed for HDI & package substrates

Si-Fly™ BP (extreme performance backplane system)

• Eye Speed® AIR™ hyper low skew 33 AWG twinax cable
• 146 differential pairs per square inch
• Samtec Flyover® Cable Technology
• End 2 design flexibility
• Cable-to-cable connectivity

Si-Fly™ MZ (high-density mezzanine system)

• Industry’s highest-density board-to-board and on-package mezzanine system
• 64 pairs in a 14 x 14 mm footprint
• Low profile design
• Up to 6.4 Tbps aggregate data rate 

FLYOVER® (OSFP 224 Gbps PAM4 Panel Assembly)

• Up to 1.6 Tbps aggregate data rate
• Eye Speed® AIR™ hyper low skew 33 AWG twinax cable
• Samtec Flyover® Cable Technology
• Excellent thermal performance
• Direct attach contacts for optimized signal integrity

If you’d like to learn more about Samtec’s 224G and 112G PAM4 products, you can find plenty of material here.

Live Proof of the Technology

Samtec tends to steal the show on the exhibit floor. The company works with its partners to bring the very latest technology proof points to any show the company attends. You can read about examples of this on SemiWiki here and here. 

This past November, Samtec exhibited at Super Computing 23 in Denver, Colorado. Ralph Page, Systems Architect at Samtec, provides an overview of what was shown at the conference here.  It is possibly the world’s first public demonstration of an asynchronous 224 G system. Here is a summary provided by Ralph of what was shown.

The demo starts with a Synopsys 224G Ethernet PHY IP that’s transmitting 31-bit, PRBS data at 224 Gbps PAM4. The 224 data travels to a Samtec Bulls Eye® test point connector, then through low loss coax to Samtec 1.85 compression mount RF connectors on a Samtec evaluation board.

The signal then goes to a Samtec Flyover® cable system, the high-density Si-Fly HD. From there, it travels through 14 inches of 34 AWG Eye Speed® ultra-low skew twinax cable, then the signal travels to end two of the Si-Fly HD connector system. From there, to a second Si-Fly™ HD evaluation board, through Samtec 1.85 mm compression mount RF connectors, to another Samtec Bulls Eye test point system on a second Synopsys 224 G PHY for analysis. The total loss exceeds 34 dBs at 56 GHz, quite impressive.

Ralph concludes by explaining that Samtec Si-Fly HD is the industry’s highest-density on-package or ASIC-adjacent cable system. High-density means it has 207 differential pairs per square inch. The figure below shows just a small portion of the complete demo layout, which takes up quite a bit of space.

Advanced system design requires high-performance communications, and Samtec delivers the complete solution to implement the required communication channels. If there is high-speed data comms in your future, you really need to check out what Samtec offers. And that’s how Samtec welcomes you to the future with proven 224G PAM4 interconnect solutions.