Cables – their presence around us is so natural that we often do not even notice them. Despite the constant pursuit of wireless technology, cables still play an essential role in our lives and are used in communication between devices. Today I would like to present those based on the USB standard. We will answer questions about how USB cables work, what types of cables are there and why USB cables have so many different ends.

How did USB cables work?

The USB standard (Universal Serial Bus) was created in 1996. It was the answer to the problem of lack of universal connector for communication of all kinds of peripheral devices with a computer, but at the same time another annoying problem was solved. Some readers still remember the times of first mobile phones, where often even different models of the same brand had different plugs. Charging your phone in the field or with friends without your own charger was a miracle! It took a while to popularize the standard, of course.

Thanks to it, you can connect many different devices to your computer, without worrying about the lack of a proper socket or driver. USB technology is also compatible with the plug’n’play standard. This is due to a number of technical solutions, but we will skip these so as not to lose the essence of the article.

USB cables – division by bandwidth

Due to the bandwidth, or simply the transfer rate, USB is divided into 3 versions:

USB 1.1

the first one improved compared to version 1.0. Presented in 1998, it allowed for a throughput of 12 Mbit/s (1.5 MB/s)

USB 2.0

The USB 2.0 cable was launched in 2000. It is still the most popular version, used by a huge number of devices. This version was named high speed and according to the documentation allows for a maximum speed of 480 Mbit/s (60 MB/s).

USB 3.0

The USB 3.0 standard was released in 2008 and brought a breakthrough increase in throughput of 4 Gbit/s (500 MB/s). In 2013, it was upgraded to 10 Gbit/sec, and four years later, the bandwidth under version 3.2 was already 20 Gbit/sec.

The next step in the evolution of the USB standard is the USB Type C standard announced in 2015, followed by its extension to USB Power Delivery. We will learn more about this in the further part of the article.

USB cables – types of plugs

As the USB standard evolved, there were many different types of plugs. In this section we will tell you about the most popular ones and their use.

USB-A cable

It’s a standard and familiar rectangular plug. It is well known that in theory we have a 50% chance of getting it right, but the tests carried out by users over the last decades put the matter in a slightly different light.

This plug is the same regardless of the standard, it is also backward compatible, also USB 1.1 will work in USB 2.0 port.

USB-B cable

It has a completely different shape, almost square and is used mainly for devices such as scanners, printers and monitors. It is popular in office equipment, measuring instruments and industry.

These two types were followed by others that responded to the development of the mobile device market. They meet the basic requirement of small size.

Mini-USB A and B cable

Once a very popular version, and today almost unheard of. If you had a digital camera, MP3/MP4 player, or navigation (yes, there used to be no smartphones), then you certainly met with such a port.

Micro-USB A and B cable

Definitely the most popular USB cable today. We meet this version almost everywhere: in phones, readers, tablets. Commonly accepted by all manufacturers, except Apple. Looking at the number of devices that use it, it will be on the pedestal for a long time.

USB-C cable

The latest technological solution. Judging by the increasing scale of its use, over time it will dethrone the micro USB. Its advantage is certainly a higher data transfer speed, the ability to deliver more power and a new, symmetrical shape, which causes no problems with plugging in the cable. The USB-C cable also allows you to transfer audio, video and charge devices with higher power requirements. This standard is used by Macbooks and the latest high-end smartphones, such as the Samsung Galaxy S9 and Huawei P20. The USB-C standard is related to Power Delivery technology, but we will talk about it in a moment.

Lightning cable

A special case of a cable using USB technology and not belonging to this “family” is the Lightning cable implemented by Apple.

Its operation is based on the same principle as described above, but has a different shape of the plug. This is the eternal quest for a different company from Cupertino.

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Although all standards, from 1.0 to USB-C, use 5V by default, improvements in charging speed are still being developed by using higher voltages. One of the standards is the Quick Charge technology, designed by Qualcomm, which allows for charging from 5V to 20V via the USB port, which means that devices equipped with Qualcomm chip can be charged up to three times faster than the 5W chargers used until recently (QC 3.0 – max 27W) . This technology is very widely used by smartphone manufacturers such as Samsung, Huawei, Xiaomi. Just look how common in phones are Qualcomm Snapdragon processors.

Other voltages are also used by technology cooperating with USB-C, called Power Delivery. It allows you to use even 20V, at 5A, which gives 100W of power. This is quite a breakthrough step, and the development of this solution will eliminate different types of power supply and plugs, which in turn will make the USB standard truly universal and completely dominate the electronic devices market.

Author: Jarosław Prorok