Intel Sees Big Future in USB Type-C
4 Things to Keep in Mind
CES 2015 attendees spotted a connector that looks sort of like a micro USB, but is way different. The USB 3.1 Type-C connector, according to the USB-IF trade organization, has a 20-year life because it’s the do-everything connector.
Intel® notes, “Two dozen Intel engineers worked on the new connector.” Look for the company to promote and support it in consumer PCs, laptops, 2:1’s and enterprise servers. And Intel’s Thunderbolt™ standard—used almost exclusively on high-end Apple machines—will undergo a speed boost to 40 Gbps and rely on the Type-C connector for Thunderbolt signals.
Here are four things you need to keep in mind for future embedded designs:
#1: It will run every serial protocol you’ve got.
At 10 Gbps and a mere 12 wires, the connector, cable, and interface circuitry are designed to not only run USB 3.1, but handle PCI Express, HDMI, DisplayPort, audio, power, and so on. Provisions in the spec allow for many of these protocols to run simultaneously and bi-directionally. For instance, USB 2.0 can run with 3.0 along with DisplayPort. This is important because one connector/cable can really do it all. The capability to run protocols simultaneously and bi-directionally simplifies the breakout connections on many embedded PCBs, panels and cases. Interestingly, while the USB-IF specs out USB 3.1 over Type-C at 10 Gbps, Intel’s Thunderbolt 3 will stream up to 40 Gbps. Clearly the design has some headroom—giving credence to the “20-year life” assertion.
#2: The connector can be inserted either way.
Like Apple’s Lightning cable concept, Type-C has no preferred insertion orientation. Hallelujah! It drives me bats how the USB A or micro USB is always the wrong way! While this is great for consumers, there are challenges for embedded designers. Most notable is the auto-sensing crossbar switch that needs to decide which side of the connector to route signals to upon insertion. There’s an “A” and a “B” side, each with 12 lines and pins. Here’s a hint: Pericom Semiconductor—a sponsor of my blog—makes a nifty crossbar designed solely for Type-C.
#3: Signal integrity’s gonna kill ya.
10 Gbps? Yeah, this is some pretty fast clocking. You’ll need to dust off your knowledge of SI eye diagrams. In FR4, the dB attenuation is wicked at this frequency and even traces on an iPhone PCB are subject to attenuation, crosstalk, jitter and other effects. You’ll pull out every trick in your SI book to keep the BER low…at the receiving end. Check out redrivers and retimers as ways to clean up your signals. Companies like Intel publish some great white papers and design guides on PCB layout tricks.
#4: Power Delivery over Type-C can light your garage.
USB 3.0 used to top out at 15W (Battery Charging BC1.2 spec), but now increases to 100W with Type-C. This is so the connector/cable can run a monitor and charge your laptop—which Apple just announced in the new MacBook. And power can flow in both directions so your laptop can run the USB 3.1 hub and monitor…or the Type-C battery-backed NAS can charge the laptop. The ICs to do all this get tricky, including the handshake protocols that amp up the power profiles for smart charging. Cypress, Maxim, Pericom, TI and others have solutions for designers.
Until we’re fully switched over to Type-C, be prepared for a drawer full of legacy adapters between the old-XYZ and Type-C. You’ll be able to see the Type-C dressed in Intel Thunderbolt 3 clothing starting in 2016.