What is the difference between USB Type C and USB 3.1/3.0? Perhaps the most detailed introduction to Type C

Everyone knows that USB has various connectors:

It is mainly divided into Type A and Type B, under which there are Micro/Mini subtypes. A real-world example: the USB cable that connects our phones and computers is USB A on one side and USB Micro B on the other. The introduction of Type C seems to mean that there is only one more shape of the USB connector, and the relationship between it and the USB 3.0/3.1 protocol should be inclusive, that is, Type C is just an extra interface defined by the USB 3.0/3.1 protocol. In fact, this understanding is wrong. In fact, USB Type C was originally proposed and Type A/B is not equal, it has its own protocol and spec, only it can support the USB Power Delivery spec (" USB PD ") fast charging protocol, Only it can provide DisplayPort and other video output, it is the future direction. This article will explain its various details for you.

USB Type C vs USB 3.0/3.1

USB has developed over the years, and we can find it on almost all electronic devices. It is also constantly evolving and increasing in speed:

The latest USB 3.1 offers transfer speeds of 10Gbps. Its interface, as mentioned earlier, has Type A and B, and these two groups of interfaces have a big problem, that is, they are directional and cannot be inserted backwards (of course, they cannot be inserted).

I'm sure we've all had the bad experience of fumbling in the dark to plug in a USB cable. In this regard, Apple's lighting interface does a good job, the same positive and negative, plug at will. Now Type C brings the same feature:

Its shape is also flatter, making it easier to make the device thinner. Note that Type C is not tied to USB 3.0/3.1, and theoretically Type C can also be applied to USB 2.0 or even 1.1, regardless of which protocol is passed on it. At this point, Type C is just a new USB interface that is more convenient. In addition, it also provides more new features than Type A/B.

More convenient connection

When we usually use USB, the general method is to connect the PC as A host with Type A and connect the device with Type B:

One on each side, different shapes, and definitely not confusing, but always pick it up and look at it to make sure you have the right end. On the contrary, Type C is not only the same as one head is inserted, there is no difference between the master and slave devices, both sides can be inserted, it can be said that you do not look at it, just pick it up, it is very convenient.

Power Delivery (PD) Fast charging technology

When USB PD 2.0 was announced in 2014, it was explicitly required to support only Type C(see Resources 1). That is to say, the Type A/B connector can support USB3.1 10Gbps speed, but it does not support PD fast Charging, and can only use the ancient Battery Charging Specification (" USB BC ") charging protocol.

PD 2.0 communicates the charging protocol by multiplexing CC signal lines.

In the case of handshake consensus at both ends, it can provide up to 20V, 5A total 100W of electric energy. Enough for laptops and low-power desktops. This is a big step up from traditional BC charging.

Note that PD charging here is very different from other fast charging. Like Qualcomm's Quick Charge and PE, are through the traditional D+ and D-line to transfer the charging protocol, itself is difficult to be compatible with PD, Qualcomm even in the QC 4.0 comprehensive reverse PD (reference 2). USB 3.1 that supports PD charging has a small battery next to the logo:

The fact that PD can provide 100W of power creates another possibility. Combine the laptop power cord and USB cable into one:

The Dock can both charge the laptop and act as a USB Hub, and the laptop has one less connection. In fact, Apple did just that more than two years ago

The ultra-thin MacBook has only one USB Type C port, which is responsible for both power and data, and the minimalist design is shocking.

Great scalability

When the USB 3.0 protocol was announced, an "Alternate Modes" was proposed, that is, other protocols can be attached to the USB protocol to pass. It was only a possibility at the time, but it really landed on the Type C. It is the Display interface protocol Display port on Type C. For those who are not clear about Display Port see: Display resolution Mystery: Who determines the size of the display resolution?

Because DP and Type C are very similar at the physical layer, a simple conversion is required:

Type C and Thunderbolt

Finally, a controversial topic: Which is more promising, USB or Thunderbolt? Obviously it's a matter of both sides of the fence.

It also supports convenient Daisy chain expansion and high-speed data transfer functions directly connected to the PC, which are not possible with the USB protocol (require Hub), but are highly required by professional users. It can also attach other protocols to the thunder protocol, such as DP, and so on, and has good scalability. At the same time, its disadvantage is also very prominent, that is expensive, the current big players only Intel and Apple, and up to 40Gbps transmission speed is over kill in many cases, USB 3.1 10Gbps is fully sufficient, only professional multi-screen 4K players need.

Their future is less clear, and in many cases, it is not the strongest technology that wins, but the result of industry gaming. We'll have to watch it for a while.

Conclusion

Martin Luther King said, "I have a dream." I also have a dream that there will be fewer wires behind the computer, preferably none. Because it's too much!! At present, wireless charging is not mature, but USB Type C is a big step toward selling a computer with only one cable. One wire to power, transmit data and display:

I believe that in the near future, the situation of messy wires will be less and less!