All about USB Type-C, this unified multifunction connector

USB Type-C is at the center of more and more devices, whether they are smartphones, laptops, or monitors. Its greatest strength is its versatility, since it is able to transmit data, video stream or energy through a single cable. However, this versatility is at the expense of simplicity, since it is difficult to determine at a glance what a USB Type-C port is capable of. We will explore the different possibilities of this one and its limits to allow you to see more clearly.

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USB Type-C is not a new USB protocol standard. It is simply a new connector that can accommodate the USB protocol, but also other protocols, such as HDMI . It is therefore very important to distinguish between the USB Type-C connector and the data passing through the cable .

We can imagine the USB Type-C connector as a pipe, independent of the flow that passes inside. And in this connector, it is possible to pass different protocols, for different uses such as:

• Data
  • USB 2.0
  • USB 3.0 (3.1 Gen 1)
  • USB 3.1 (3.1 Gen 2)
• Audio & Video
  • DisplayPort video feed
  • HDMI video stream
  • Audio stream (USB Audio)
• Energy
  • Standard charge
  • USB Power Delivery for fast charging

The most complicated is that in some devices, USB Type-C ports can support some versions of the USB protocol, but not the video or power protocols. To take a concrete case, a port can be certified USB Power Delivery, but be limited to USB 2.0 in terms of data . Similarly, a connector support the USB 3.1 Gen 2 without being able to pass an HDMI stream, or without supporting USB Power Delivery.

And there is unfortunately no guarantee regarding the functionality of the Type-C USB port on your smartphone. It will therefore be necessary for manufacturers to play the game to know what is possible and what is not, by clearly displaying on the product sheet or the box the characteristics of the USB Type-C onboard.

Finally, note that conventional connectors (USB Type-A and micro USB) can also pass data in USB 3.1, 3.0 or 2.0. However, they can not pass video streams or USB Power Delivery.

Data

First, a little clarification on the data transfer protocols. If, for the sake of clarity, we often talk about USB 3.0, and USB 3.1, this name is not quite accurate. Indeed, the USB-IF (the organization in charge of USB standards ) has renamed the USB 3.0 to USB 3.1 Gen 1 (with a bit rate of 5 Gb / s), while the USB 3.1 Gen 2 refers to USB 3.1 (with its 10 Gb / s rate). If you cross these denominations, do not be surprised to find either USB 3.1 Gen 1, USB 5 Gb / s or USB 3.0 in the features of products you intend to buy.

Note that we will not address in this folder Thunderbolt 3 protocol , much faster than USB 3.1, which also uses the USB Type-C connector, but is currently reserved for computers and raises issues even more complex .

USB 2.0

Who can do the least? A USB Type-C connector can carry data with the USB 2.0 protocol, also known as “Hi-Speed ​​USB”. In fact, this is the case of the first smartphones in USB Type-C. Whether you have a premium smartphone such as a Google Pixel or a much cheaper smartphone such as a Wileyfox Swift 2, the maximum speed will be the same, namely the 480 Mb / s of the old USB 2.0.

USB 3.1 Gen 1

There are, however, some smartphones with a USB Type-C port supporting higher speeds, although the list is still very limited. The  LG G5 and HTC 10  for example can enjoy speeds up to 5 Gb / s enabled by USB 3.0. This is unfortunately not a marketing argument and if HTC has continued to integrate this connector on its U11 , this is not the case of LG that is ironed to USB 2.0 on the LG G6 .

USB 3.1 Gen 2

It’s even easier for smartphones with a Type-C port supporting the protocol in its latest revision, USB 3.1 Gen 2 or “Superspeed + USB 10 Gb / s”. It just does not exist , to our knowledge at the moment. It remains to be seen if the manufacturers will first go to USB at 5 Gb / s or if they decide to go directly to the 10 Gb / s protocol. We can doubt especially when today, it is increasingly easy to share wireless files, photos and sounds that you want without cluttering son.

Now let’s see what the USB Type-C connector can carry with regards to audio & video.

USB 3.2

In 2017, the USB 3.0 Promoter Group announced the USB 3.2 standard . Taking advantage of the multi-lane and fully exploiting the 8 SuperSpeed ​​cables contained in each USB cable, this new standard doubles the transfer rates to reach 20 Gb / s, or 2.5 Gb / s (theoretical data rates for a single USB cable). 1 meter cable). The advantage of this standard is that it does not need to change cables (as long as they are USB 3.1) since they already have the 8 SuperSpeed ​​cables. The target device (smartphone, computer …) must however be compatible.

Audio and video

Within the specification of the USB Type-C is a convenient feature, which you may hear if you are interested in this topic: Alternate Mode . It is this part of the specification that allows a variety of video and audio protocols to pass through the USB Type-C. Thus this alternative mode, in reference to the main mode (which was to pass data, as always on the USB) allows to pass several protocols, as shown below.

DisplayPort

The USB Type-C has been able since late 2014 to carry a DisplayPort 1.3 signal through Alternate Mode , as shown below. With DisplayPort 1.3, it is possible to connect two 4K screens at 60 frames per second or a 5K screen.

VESA, the standard DisplayPort organization, announced the arrival of DisplayPort 1.4 support for USB Type-C. This allows to support an 8K stream (7680 × 4320 pixels, more than 33 million pixels against 8 million pixels for the 4K UHD) at 60 frames per second, or the support of the 4K to 120 frames per second.

HDMI

Always in the video range, the USB Type-C connector can also carry an HDMI signal . Although this is a common outlet, unlike the DisplayPort, you can pass an HDMI signal either through a standard HDMI cable or a USB Type-C cable. This year, IFA saw the first USB Type C cables passing an HDMI  1.4 signal , thus limited to a stream of 3840 by 2160 pixels at 30 frames per second.

Audio

Finally, the all-purpose connector USB Type-C is not limited to video, and it can also pass an audio signal  with the new standard USB Audio, more complete than the previous one . Convenient in these times when some brands have the “courage” to remove the jack. However, we are not convinced that we would win at the change.

Energy

Finally, the last important point about the USB Type-C connector is its power management devices. This is perhaps what has been the most publicized, given the consequences of failures that poor quality cables, not meeting the standards, can lead . This has also led the USB-IF, the body responsible for the USB standard to decide on the implementation of chip in the cables so that accidents can not happen .

As a reminder, up to now, it was possible to supply 5 V at 500 mA to a USB device, ie 2.5 Watts. As part of the definition of the new Type-C connector, it is now possible, thanks to the Power Delivery specification to deliver up to 100 watts. Indeed, the Type-C introduces several profiles, ranging from 10 Watts to 100 Watts, as illustrated below.

To go beyond a current of 1.5 A or a voltage of 5 V, it is necessary to have special cables.

Towards a simpler future

If the USB Type-C connector is confusing, we hope that this folder should allow you to see a little more clearly. This new connector should all make our life easier in our interactions with our different devices. It’s still the first time in the history of electronics and computing that a single cable can do it all. In addition, it offers a reversible port so you do not have to try to connect unsuccessfully, in the dark, a USB device.

Still, the adoption of this connector is still slow. Even today, in 2018, we see many smartphones entry-level (or mid-range), out with a microUSB, and do not talk about accessories such as external batteries and Bluetooth headsets …