USB Type-C Connector Specifications Finalizedby Brett Howse on August 12, 2014 11:50 PM EST
Today it was announced by the USB-IF (USB Implementers Forum) that the latest USB connector which we first caught a glimpse of in April has been finalized, and with this specification many of the issues with USB as a connector should be corrected. USB, or Universal Serial Bus, has been with us for a long time now, with the standard first being adopted in 1996. At the time, it seemed very fast at up to 12 Mbps, and the connector form factor was not an issue on the large desktop PCs of the day, but over the years, the specifications for USB have been updated several times, and the connectors have also been updated to fit new form factor devices.
In the early ‘90s, when USB was first being developed, the designers had no idea just how universal it would become. The first connectors, USB-A and USB-B, were not only massive in size, but the connection itself was only ever intended to provide power at a low draw of 100 mA. As USB evolved, those limitations were some of the first to go.
First, the mini connectors were introduced, which, at approximately 3 mm x 7 mm, were significantly smaller than the original connector, but other than the smaller size they didn’t correct every issue with the initial connectors. For instance, they still had a connector which had to be oriented a certain way in order to be plugged in. As some people know, it can take several tries to get a USB cable to connect, and has resulted in more than a few jokes being made about it. The smaller size did allow USB to be used on a much different class of device than the original connector, with widespread adoption of the mini connectors on everything from digital cameras to Harmony remotes to PDAs of the day.
USB Cables and Connectors - Image Source Viljo Viitanen
In January 2007, the Micro-USB connector was announced by the USB-IF, and with this change, USB now had the opportunity to become ubiquitous on smartphones and other such devices. Not only was the connector smaller and thinner, but the maximum charging rate was increased to up to 1.8 A for pins 1 and 5. The connection is also rated for at least 10,000 connect-disconnect cycles, which is much higher than the original USB specification of 1,500 cycles, and 5,000 for the Mini specification. However once again, the Micro-USB connector did not solve every issue with USB as a connector. Again, the cable was not reversible, so the cable must be oriented in the proper direction prior to insertion, and with USB 3.0 being standardized in 2008, the Micro connector could not support USB 3.0 speeds, and therefore a USB 3.0 Micro-B connector was created. While just as thin as the standard connector, it adds an additional five pins beside the standard pins making it a very wide connection.
With that history behind us, we can take a look at the changes which were finalized for the latest connector type. There are a lot of changes coming, with some excellent enhancements:
- Completely new design but with backwards compatibility
- Similar to the size of USB 2.0 Micro-B (standard Smartphone charging cable)
- Slim enough for mobile devices, but robust enough for laptops and tablets
- Reversible plug orientation for ease of connection
- Scalable power charging with connectors being able to supply up to 5 A and cables supporting 3 A for up to 100 watts of power
- Designed for future USB performance requirements
- Certified for USB 3.1 data rates (10 Gbps)
- Receptacle opening: ~8.4 mm x ~2.6 mm
- Durability of 10,000 connect-disconnect cycles
- Improved EMI and RFI mitigation features
With this new design, existing devices won’t be able to mate using the new cables, so for that reason the USB-IF has defined passive cables which will allow older devices to connect to the new connector, or newer devices to connect to the older connectors for backwards compatibility. With the ubiquity of USB, this is clearly important.
There will be a lot of use cases for the new connector, which should only help cement USB as an ongoing standard. 10 Gbps transfer rates should help ensure that the transfer is not bottlenecked by USB, and with the high current draw being specified by connectors, USB may now replace the charging ports on many laptops as well as some tablets that use it now. The feature that will be most helpful to all users though is the reversible plug, which will finally do away with the somewhat annoying connection that has to be done today.
As this is a standard that is just now finalized, it will be some time before we see it in production devcies, but with the universal nature of USB, you can expect it to be very prevalent in upcoming technology in the near future.
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OreoCookie - Wednesday, August 13, 2014 - linkWhere did you get the numbers on the failure rates, I'm curious? It's always dangerous to extrapolate from personal experience or to try and make statistics from ratings of products on online stores. But the 1.5 star average certainly says something. My first Lightning cable (I keep one in the office and one at home) has some bulges right before the plug from the mechanical stress, but that's not a problem of the plug design but rather the cable itself.
The only problem I've had was with the actual Lightning connectors was that lint had accumulated in my iPhone's charging port and so it wouldn't charge properly. The iPhone's SIM tool took care of that. (A problem that is to some degree shared by micro USB devices, but those are usually not in my pocket.)
Moreover, a few years ago my dad's computer was fried by a faulty USB hub, so yes, I'd prefer some protection and not just a dumb cable. But that's a problem which cannot be solved by a new USB plug. While I am not thrilled by the costs of Lightning cables, I think active cables are the way of the future, and that extra costs are mitigated when this fictitious connector becomes ubiquitous.
I think that the Lightning design is mechanically more robust than, say, a micro USB plug, because it uses way more material. And I'm not sure the casing does anything to prevent oxidation of the contacts, especially if it is used like the majority of USB cables is: they stay plugged into a device.
You're right that there are problems associated to exposed pins, but I reckon you can take care of those. This USB-C adapter seems DOA to some degree (I currently have four different mutually incompatible USB plugs in my house), because there is a push towards ever smaller devices and very often the limiting factor are plugs (just have a look at MacBook Airs or similar devices, they are not much thicker than the USB plugs). A Lightning-style connector would allow for significantly smaller ports.
UpSpin - Wednesday, August 13, 2014 - linkI think it was obvious that I simply took the 1 star reviews from the Apple site and set it in relation to the 5 star reviews to estimate a failure rate according to Apples own online store. Yes, it's inaccurate, but I simply was surprised by the low rating.
You can also buy a cheap Lightning cable knock off and surely fry your iPhone or iPad with it.
Every USB port on a proper device is protected.
According to the chipwork links the Lightning connector does not have some sort of galvanic isolation. So the cable protects your device from overvoltage spikes the same way a passive USB cable does. The mentioned protection is related to Apple, so that 3rd party manufacturers can't produce such cables easily. The mosfets are used to prevent a shortage and corrosion, which isn't necessary on other cables whose contacst aren't exposed.
sweenish - Thursday, August 14, 2014 - linkSimply having more material does not make a great leap to more mechanically sound. How is it implemented, what is the material, have the batches been strength tested, etc.?
You can't make an airplane out of just any aluminum and say you're good just because you used more material.
steven75 - Wednesday, August 13, 2014 - link"Failure by design." LOLWUT. Haters gonna hate!
UpSpin - Wednesday, August 13, 2014 - linkThe failure by design was related to the openly accessible contacts.
Connections with an applied voltage which can get easily in contact with electrolytes suffer from corrosion. One of the reasons Apple has to implement ICs in the cable.
Additionally gets oil or dirt much easier on the contacts if you can touch them with your oily dirty fingers adding some resistance to the contacts. This however casuses contact problems, heat and finally destroys the connections.
Most of the images you can find about the issues with Lightning connector are however related to the fragile cable relief, which is something they can fix.
But the other thing is a design issue. The corrosion can get slowed down with the active control of voltage in the cable itself. The contact problems however, not. So that's a failure, or issue, by design. Of course the Apple connector has some advantges, too (more rigid) but also serious disadvantages.
OreoCookie - Wednesday, August 13, 2014 - linkMany plugs have openly accessible contact, the ubiquitous copper-based ethernet plugs come to mind. So I think these are problems with a solution. Also the fact that you need silicon to make the cables work doesn't faze me, if it's necessary, it's necessary.
You're are of right that Apple's design of the Lightning connector comes with trade-offs, but I think they optimized for the right thing, size: with the current USB design, I don't think you can shrink the plug without compromising structural rigidity too much, and size is the most important thing if you want to have a plug that will stay with us for several years to come. It should be the standard plug on anything from an ultra thin Pebble/Whatever Smart Watch to the new Samsung Galaxy S10. Here, I don't think USB-C will deliver. Instead, it'll be the fifth mutually incompatible USB cable lying around (I have two types of big USB cables for external hard drives, a mini USB cable for my dslr and a micro USB cable for my card reader). The fact that you need silicon in the cables is just an implementation detail that won't really matter once they are main stream.
You write that most images of faulty Lightning connectors feature frayed cables, and I agree. But that's hardly a problem of the plug, but nevertheless should be a problem that's fixed. Especially if cables cost ~$20 a pop, Apple has no excuse to skimp here.
Ethos Evoss - Thursday, September 25, 2014 - linkplease what lightning that is crap useless !! usb is standard and that should stay !
willis936 - Wednesday, August 13, 2014 - link10 Gbps are they joking? That's an optional feature that most people won't be paying for right?
Hrel - Wednesday, August 13, 2014 - link1. I think you're confused about the difference between 1Gbps and 1GB/s.
2. It's not like it's making the product substantially more expensive, you'll be fine.
3. SSD's today could saturate that fully.
4. Are you SERIOUSLY complaining about progress? Advancement of technology? Faster speeds?!
willis936 - Wednesday, August 13, 2014 - linkI'm intimately aware of what a 10 gig phy is and yes I am complaining about it because it costs a lot more than you think. Do you think faster speeds magically appear because "technology advances". Lower power! Faster speeds! It's copper. You need to charge the channel and no matter how good "technology gets" you're fighting physics. Display techs have taken years to bump past 3 gig, 802.3 has been sitting at 1 gig for roughly a decade. Thunderbolt offered really high speeds and No One Used It because it cost too much for unnecessary speeds. USB wins for low cost and ubiquity.