Shulou(Shulou.com)11/24 Report--

Original title: "after reading this article, there is a USB interface that you do not know, you come to me!" "

Excuse me, is there a data line?

In other words, the editor's seat is in the first row of the office area, opposite the company's most luxurious and most frequently used conference room. How high is it? Booking a conference room is like snapping up a train ticket-the kind that can't be booked half a minute later and open two days in advance.

Therefore, the editor will be accosted by different people every day, all sorts of strange excuses.

"Hello, classmate. Do you have a pen?"

"handsome, is the data cable in use?"

"Children, what kind of charger do you use for your mobile phone?"

"Hey,man, could you take a picture for us?"

……

The demand for ranking No.1 is absolutely "borrow data cable", Android data cable, Apple data cable, Type-C data cable, Micro USB data cable. Clearly know that their own needs are good, do not know that the only description of the requirements will be described for half a day, and so know the specific needs, the meeting may be over.

In order to minimize the time to take up better service colleagues, I made the following picture.

From then on, when I meet the need to borrow data cable again, I will pull out this picture silently.

Yes, the USB interface is such an existence that everyone can't do without, but it makes people bald because of too many kinds.

In daily life, in addition to mobile phones, in fact, many devices will also use the USB interface, such as mobile portable battery, printers, digital cameras and so on. Although the interfaces connected to the computer side are mostly the same, the interfaces connected to the device side are different.

Then we can't help but ask, how many kinds of USB interfaces are there?

USB Transport Standard before introducing the USB interface, let's take a look at the USB transport standard. After all, the standard determines the speed.

Since USB-IF (USB Implementers Forum) issued the USB 1.0 standard in 1996, the USB standard has experienced the development of more than USB 1.1, USB 2.0, USB 3.0, USB 3.1, USB 3.2. In 2019, USB-IF released the latest USB4 standard, which brought a new standard specification to the USB interface.

Seeing the table above, some students may have questions. Where are USB 3.0and USB 3.1s?

In fact, there are a few short stories about the official renaming.

Three, to be exact!

The first renaming: in 2003, USB-IF renamed USB specifications and standards, renaming USB 1.0 to USB 2.0 low Speed (Low-Speed) version, USB 1.1 to USB 2.0 full Speed (Full-Speed) version, and USB 2.0 to USB 2.0 Expressway (High-Speed) version.

Second name change: shortly after the release of USB 3.1 in 2013, USB-IF changed its name to USB 3.1Gen1,USB 3.1to USB 3.1Gen2. But this renaming has brought trouble to consumers, many profiteers only marked the product packaging to support USB 3.1, but did not mark whether it is Gen1 or Gen2, the two transmission performance is so different that consumers will fall into the trap if they are not careful.

The third renaming: in 2019, USB-IF changed its name from USB 3. 1 Gen1 (formerly USB3.0) to USB 3. 2 Gen1,USB 3. 1 Gen2 (formerly USB 3. 1) to USB 3. 2 Gen2 x 1 and USB 3. 2 Gen2 x 2. (for the convenience of description, we will refer to it as supporting the USB 3.0 standard later.)

Knock on the blackboard!

Students, the next time you buy a U disk, data line and other products, you must carefully see which standard the product supports, and don't be fooled by vendors.

Hit the blackboard for the second time!

In the standard way of writing "USB4", there is no space between "USB" and "4"! Pay attention to screening when new products are on the market.

After the USB interface standard understands the USB transport standard, let's look at the specific USB interface standard. USB interface can be divided into three types: standard USB interface, Mini USB interface and Micro USB interface.

The standard USB interface, which is divided into Type-An and Type-B, looks as follows:

According to the different USB standards supported, Type-An and Type-B can be divided into USB 2.0 and USB 3.0 standard USB interfaces. Depending on the color of the interface, it is easy to tell whether the interface supports USB 2.0 or USB 3.0. Type-An interface is also the most common USB interface in our daily life, which is widely used in mouse, keyboard, U disk and other devices, while Type-B is often used in printers, special displays and other devices.

The Mini USB interface is a small USB interface with the same index as the standard USB, but adds ID pins (used to distinguish whether the device is a host or a peripheral) to support OTG (On The Go, which allows data transfer between devices without a host). Mini USB APIs are mainly divided into Mini-An and Mini-B, which are as follows:

Because of its relatively small size, Mini USB interface is commonly used in some small devices, such as MP3, MP4, radio and so on. It is also used in some models of mobile phones.

The Micro USB interface belongs to the next generation specification interface of Mini USB. The plug of the Micro USB interface is made of stainless steel, and the plug life is increased to 10000 times. Compared with the Mini USB interface, the height is halved while the width is almost the same, and it is more compact. Micro USB APIs can also be divided into Micro-An and Micro-B, as shown below:

I believe we all know the USB interface of Micro-B type, but we just don't know its professional name. in the early stage of the development of smartphones, the vast majority of smartphones (except Apple phones) use Micro-B interface as the charging and data interface. After the release of the USB 3.0standard, the Micro-B interface also has a new shape, which is no stranger to everyone. Most of the mobile hard drive boxes that we buy that support USB 3.0use this interface.

Type-C interface is a new type of USB interface that has emerged in recent years. I believe the greatest advantage of this interface for users is that it can be plugged in and out.

According to statistics, the average person wastes 30 minutes per year plugging in USB! The first time can not be plugged in, many times to doubt life, and finally found that the first time is right, the next N attempts are only small twists and turns in life, with the type-C interface can finally be done at once. The Type-C API looks as follows:

At present, the latest USB4 standard only supports Type-C interface, and USB4 adopts Thunderbolt protocol (commonly known as lightning interface protocol, which is developed by Intel, which has the characteristics of high speed, strong power supply, and can be compatible with multiple interfaces / protocols, such as lightning, USB, Display Port, PCIe and so on). Therefore, the Type-C interface that supports USB4 standard can also be compatible with lightning interface. In this way, the Type-C interface is the trend of the times.

USB transport standard and interface finally, a picture summarizes the supporting relationship between USB transport standard and interface for your reference.

* Note: the transmission rate indicated in the table is the maximum transmission rate supported by the standard. Have you failed to learn so many USB interfaces?

This article comes from the official account of Wechat: ZTE documents (ID:ztedoc)

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