The USB Promoter Group recently announced the November release of the USB4 Version 2.0 specification, a significant update to enable up to 80 Gbps of data performance over the USB Type-C cable and connector. The USB Type-C and USB Power Delivery (USB PD) specifications will also be updated to enable this higher level of data performance.
As a result, USB connector and cable developers are busy re-branding and re-marketing current USB4.0 40G per-link products as USB4.2 80G ones. Some USB4.0 interconnect products will likely go through new compliance and interoperability testing, and other certifications. Other USB4.0 optional 20G link cables and connectors are unlikely to meet the new requirements.
The new USB 80G link will likely increase the volume and market share in camera security networks and machine vision segments. AR/VR, 8K, gaming, and other AV applications are drivers of another booming growth target. We might also soon see USB4.2 80G link receptacle ports in new vehicles starting late next year.
Until then, expect a new distinctive logo on cable plugs and device faceplate ports once the 80G products are certified. Let’s review the possibilities for the different types of cables and connectors.
Protocol updates are also in the works to enable higher-performance USB 3.2, DisplayPort, and PCI Express (PCIe) data tunneling to best use the higher available bandwidth.
Passive copper
It’s expected that each of the USB4.2 two lanes of differential twin-axial pairs will run at 40G PAM4 per lane, creating an 80G PAM4 link using USB Type-C connectors. However, it’s possible another type of signaling will be used. We’ll have to wait and see.
Technically, a user can use the current USB4.0 20G NRZ per-lane connectors and cables with the current USB Type C connectors and cables. But it seems that most product developers will prefer to market their new 80G port devices with a fresh USB4.2 logo. A distinctive USB 80G logo could also be used on the over-mold plugs.
Regardless, buyers and users should be aware of the various levels of cable assembly product performance and price.
Active copper
Changes to the USB Type-C and USB Power Delivery specifications could affect the qualification and certification testing for active copper extenders, such as linear accelerators and repeater chip types.
Active copper USB chips are also used to keep the link reach cable diameter as small as possible. Suppliers are keeping a low profile as they support mass consumer extender cable assembly volumes for global entities like Amazon and other large re-sellers.
Third-party signal integrity and performance testing are key requirements for USB product launches. The time to market is achieved using a Tier 1 test-bed solution product set like the one offered by Wilder-Tech, an expert in USB4.0 and USB4.2, as well as all USB, HDMI, and DisplayPort product generations.
Here’s a look at the USB4.0 product information.
Active optical
USB3.0, USB3.1, and USB3.2 Type A, Type B, and Type C active optical cables (AOCs) are well-established long-reach products available in several useful configurations — including right-angle plugs. These products have been supporting the prosumer and professional AV markets.
These products support applications like AR/VR, vehicle AV, machine vision, micro-storage, security networks, and several types of PCs and peripheral devices. Additionally, 8K displays, TVs, and 16K cameras are other market segments for the new AOCs.
Here are images of the typical Type A and C USB AOC products.
So, what can we expect for AOC USB4.2 products at the November USB Summit? Expect a new USB Hub box with USB 80G receptacle ports. Type A and C AOC versions will likely experience an acceleration in 2023 shipments.
It’s also possible that new chips supporting the 80G AOC links will be on display, but some might be private label chips embedded in over-molded or hard-shell plug and receptacle connectors. Like most new products, they’ll be most costly at first, but as the volume and competition grow, the prices will gradually decrease.
Related 80G+ link applications
Here are some more possibilities for the 80G+ link applications. A double-stack, over-molded cable plug could connect to SMT top and bottom-side USB 4.2 receptacles — which could be used for fanouts or 160Gbps trunk or fanout links.
It will be interesting to see how the USB4.2 80G specifications will provide better DisplayPort and PCIe support. These USB4.2 specifications and new products will have backward compatibility and support installed USB1, USB2, USB3.0, USB3.1, USB4.0, and Thunderbolt products and networks.
The market was only offering the lesser performing 20Gbps cables, so Intel and Apple launched the Thunderbolt 4.0 40Gbps specification, which maintains a higher level of performance. It also uses passive Type-C links running multiple 4k displays at 32G per link.
DisplayPort 2.0 80G cables use four lanes of 20Gbps for 80Gbps link performance. The USB4.2 uses the same Type C connector, as well as two lanes of 40G PAM4 per 80G link. An alternative is the USB4.2 could use four lanes using 20G each. Or perhaps it will enhance the DisplayPort link performance option using two lanes of 40G PAM4.
HDMI 2.0 Ultra-High-speed supports 48G links using Type-C connectors. What will be this interface’s next speed rate? Again, we’ll have to wait and see. The USB4.2 40G lanes can already support PCIe 5.0 32G per-lane systems, at least by tunneling.
Observations
Keep your eye on usb.org for key updates. The ideal internal USB4.2 copper cable design will harmonize with external copper cables to maintain performance. This is typically done for high-speed interface links running at 56G PAM4 and 112G PAM4 per lane.
There’s a smaller amount of USB4.0 products and marketing collaterals available currently. The core USB developers are evaluating and working on potential roadmaps and are likely doing USB5.0 160G link technology R&D. It’s anticipated many will publicly launch their USB4.2 products at the USB Summit. The USB4.2 products won’t replace the USB4.0 ones until next year as the market first tests them out.
At the next speed rate, it may be necessary to use active copper and active optical instead of passive copper links. There may be a future USB Type C or D connector hybrid (copper and optical) to support power delivery.
The USB4.2 ruggedized connectors and cables will likely be available as they are for USB3.2. But will the internal USB4.2 embedded chips, cables, plugs, and receptacles reliably handle liquid ASIC cooling or immersion environment applications?
Look for new topology solutions using USB host-to-host fabric switching that supports large security systems with next-generation cameras and sensor networks. Also, expect to see USB micro-datacenter networks for mobile applications potentially.
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