Universal Serial Bus, or simply USB, is an industry standard developed in the mid-1990s to standardize the connection of peripherals to a computer. It has replaced most interfaces and is now the most common connector type for consumer devices.

Today, almost every device, whether portable or stationary, has various types of USB connectors. But everything is much more complicated than beginners think. Today we will look at the types of USB ports and various standards.

Many might now be asking the question: “If USB should be universal, then why does it have a large number of types?” The fact is that all these types of USB connectors perform different functions. This helps ensure compatibility if a device with improved specifications is released. Let's look at the most common types of USB ports.

• Type-A- most cables have a connector of this type of USB at one end, this also includes cables of modern keyboards and mice. The same type of USB is supplied with personal computers and chargers;
• Type-B- This port is used to connect printers and other peripheral devices to the computer. But it's not currently as common as USB Type-A;

• Mini USB- This was the standard connector for mobile devices before the advent of Micro USB. This connector is smaller than the standard one, as can be understood by its name. This type of connector is also a little outdated and has been replaced by Micro USB, but this does not mean that these types of USB cannot be found anywhere;
• Micro USB- is currently the standard for portable devices. All major mobile device manufacturers have adopted it, with the exception of Apple. But Micro USB is gradually beginning to be replaced by USB Type-C. By the way, there are different types of Micro USB connectors, but we’ll talk about that a little later;
• Type-C- such a cable can have the same connector at both ends. Claims faster data transfer speeds and higher power compared to previous USB standards. This is the connector Apple used for Thunderbolt 3. We’ll talk about USB Type-C a little later;

• Lightning- does not belong to the USB standard, but has been a proprietary interface for Apple mobile products since September 2012. Until that time, devices used a less compact 30-pin proprietary connector.

USB 3.0

The new standard provides higher data transfer rates while being backward compatible with the old standard. In form, USB 3.0 and USB 2.0 Type-A are the same, it’s just that the new standard is colored blue to distinguish USB 3.0 from 2.0.

But the speed increase will only occur if the connector where the cable or flash drive is inserted must be USB 3.0, and the cable or flash drive itself must have a USB 3.0 connector.

Also, in addition to USB 3.0 Type-A, there are other types of USB 3.0 connectors. Type-B and its Micro version have additional pins to provide higher data transfer speeds, which breaks the compatibility of these connectors with older versions, but older USB 2.0 devices can be plugged into the new USB 3.0 connectors, but you will not get a speed boost.

Micro USB

If you have an Android device, then you need to have a Micro USB cable. Even the most ardent Apple fans can't avoid this type of connector in portable batteries, speakers and more.

There are also divisions into types of Micro USB connectors. Micro USB Type-B is mainly used, Type-A is not particularly common, and I have never seen it in real life. The same applies to Mini USB.

If you start buying a lot of gadgets, you will soon start using different wires for different devices, still there is no difference. So you don't have to buy additional wires if you don't lose or break them.

When buying a cable, people usually buy the cheapest ones, which I do not advise you to do, since the quality of such products can be very poor. This will lead to cable failure in the future.

Also decide on the length of the cable. A short cable is convenient when traveling, but at home with this you will be sitting on the floor near the outlet. A long cable will get tangled and interfere with you in every possible way. For a portable battery, I have a cable 35 centimeters long, and a cable for charging a smartphone at home is 1 meter long.

USB On-The-Go

USB On-The-Go (USB OTG) is a relatively new standard that allows you to insert flash drives designed for other USB interfaces into portable devices, cables to charge something from the battery of your portable device, and so on. USB OTG supports not only USB Type-A, but also other types of USB ports.

Now imagine that you have an external hard drive, a smartphone and a laptop. What steps will you follow to move any file from external hard drive to your smartphone? The easiest way is to first move the file from the external hard drive to the laptop, and from there to the smartphone.

Now imagine that you have a USB OTG adapter. Just insert the adapter into your smartphone and the cable from the external hard drive into it. There is no need for a laptop. Comfortable?

Unfortunately, not all devices support USB On-The-Go, so before purchasing an adapter, I advise you to check your device for USB OTG support.

Adapters for Lightning exist and they work everywhere even with iOS 9, but I don’t really want to call it OTG.

USB Type-C

This new standard has great potential for the future. Firstly, it is fast and can transmit large currents, and secondly, it can be inserted either way and there can be the same connector on both ends of the wire.

In 2015, Apple shocked the whole world by releasing a MacBook with one USB Type-C connector. This could be the start of a trend.

Now there are many devices with a USB Type-C connector. To connect to a computer, you should use a USB Type-C to USB Type-A cable if you do not have the same connector on your computer.

It’s not worth buying cheap USB Type-C cables, it’s not worth it at all. It's very easy to kill your device. In addition, large currents pass through such a cable, so a low-quality cable will also lead to a fire. Don't spare money on a quality cable.

conclusions

Today we looked at various types of USB connectors and standards. Now you know all the popular types of USB connectors. I hope this information was useful to you. If so, please take the time to rate this article below.

Mini USB is already losing its position in the market, and is being replaced by its analogue - Micro USB. The key feature of Micro USB is its compact design. At the same time, Micro USB is capable of providing no less speed of data transfer from one media to another. Unlike Mini USB, the new variety takes up much less space on the printed circuit board (about half as much). It is believed that this parameter is fundamental when designing small gadgets, such as mobile phones, digital cameras, pocket personal computers, players, etc.

The main differences between Micro USB and Mini USB

Micro USB has a compact plug design based on USB 2.0. This improved type of USB has been used everywhere since 2011. It is used to charge and transfer data to each new mobile device. This is primarily due to the fact that modern manufacturers of gadgets and other small devices have come to the conclusion that a huge number of different connectors for charging and data transfer is impractical. Thus, it turns out that every new device, be it a phone, tablet or something else, has a standard connector - Micro USB.

As mentioned above, Micro USB differs from its predecessor primarily in its small size. In addition, it is several times stronger than the previous type of USB. The thing is that it is covered with stainless steel and also supports the USB On-the-Go specification. The peculiarity of this specification is that it ensures data exchange between two end devices without any additional equipment (computer, laptop, etc.).

The Micro USB connector itself has three types of plugs, these are: Micro A, Micro AB and Micro B. The difference between them, as you might guess, is the size of the plug, plugs and sockets. This is where the main differences end. The Micro USB cable itself consists of four conductors. Two of them perform the role of transmission, data exchange, and the other two are for power supply, with a voltage of up to 5 volts (that is, for charging the device). As for the visual component, Micro USB on one side has a Micro A, Micro AB or Micro B plug, and on the other end there is a regular USB input for connecting to a charger, personal computer, etc.

Alternative connection methods, such as USB connectors, are widely used to connect modern devices.

This name is quite common and is translated from English as “universal serial bus”.

All USB connectors are available in three versions.

Characteristic features of the main three versions of USB connectors

The first version of USB connectors (1.1). Its characteristic feature is a very low speed, at which all information is transmitted with a long delay.

The transfer speed is 12 Mbit/s. Its main purpose is to be used for interconnecting devices.

Second version of USB connectors (2.0).

Characterized by a data transfer rate of 480 Mbit/s. This corresponds to a speed of 48 MB/s.

The bulk of all modern technical instruments and devices are adapted to use this particular version. It is the most popular and well-known, and therefore is in demand in the electrical goods market.
True, due to many factors, the real speed of this standard does not exceed 30 - 33 MB/s.

Since the latest releases of hard drives, for example, SSDs, are designed to read information at a much higher speed (almost 4 times), this version of the standard delays the effect of new drive models.

This shows the main drawback of the properties of USB 2.0 connectors. But despite this, certain devices are quite compatible with this version of connectors: mice, keyboards, scanners and printers.

Third version of USB (3.0).

This version is characterized by the speed of information transfer – 5 Gbit/s – which is considered a fairly high figure.

This speed corresponds 500 MB/s

This is much higher than the speed of the latest generation hard drives (150 - 170 MB/s).

USB 3.0 connectors are specially marked blue for recognition.

Interface compatibility

If we consider the issue of compatibility of devices that have the connectors presented above, we can state that the first and second versions of USB connectors can be interchangeable with each other.

A particular device that has a USB version 2 connection but accepts a version 1 connection may display a message indicating its ability to perform faster.

Because this computer model is designed to receive information through the second version, the speed of which is higher than the first.

That is, the full speed potential of this device will not be used.
Modern devices that have connectors of the second version can be connected to the third version of USB, and the use of the third version relative to the second is excluded, except for USB 3.0 type A.

Additional contacts create conditions for increasing the speed of the interface - this is a feature of the latest models of cables and devices that have connectors of the third version of USB.

USB power supply

The power for which connected devices with USB connectors are designed is 2,5 W and also 4,5 W (for the third version).

Based on this, USB connectors of all versions require voltage 5 V. Current up to 0,5 Oh, and for the third version - 0.9 A.

USB 3.0 pins.

Devices such as players, memory cards, phones, flash drives (that is, devices with low power) can be freely connected using such connectors.

And technical means with high power are connected to an external electrical network.

Connector types

The second and third versions of connectors are distinguished by size: Mini USB (small sizes), Micro USB (even smaller sizes); and also by types: A, B.

USB 2.0 type A connector.

A reliable connector whose main characteristic is the ability to withstand more than one connection without losing its integrity.

The cross-section of the connector has a rectangular shape, which creates additional protection when connecting.

Its disadvantage is its large size, and all modern devices are portable, which influenced the development and production of connectors of a similar type, but of a smaller size.

USB 2.0 Type A was introduced in the nineties and is currently still the most used.

A significant number of low-power devices have it: keyboard, mouse, flash drive and others.

USB connector version 2.0 type B.

We mainly find its application in stationary devices of large dimensions. These include scanners, printers, and less commonly ADSL modems.

It is rare, but it still happens that cables of this type are sold separately from the equipment itself, because they are not part of the technical device kit. Therefore, check the complete set of devices.

Connectors of this type are not as popular as type A connectors.

The square and trapezoidal shape is inherent in all type B connectors.

These include both Mini and Micro.

The peculiarity of the cross-section of type “B” connectors is their square shape, which distinguishes it from other types.

Mini USB connectors of the second version, type B.

The name of this type of connector indicates that it has very small dimensions. And this is not surprising, because the modern market increasingly offers miniature goods.

Thanks to the use of personal hard drives, card readers, players and other small devices, USB Mini connectors related to type B have become very popular.

It should be noted that such connectors are unreliable. It becomes loose with frequent use.

But the use of USB Mini Type A connector models is extremely limited.

Micro USB 2.0 type B connectors.

Micro USB connector models are more advanced than Mini USB models.

This type of connector is incredibly small in size.

Unlike the previous mini types presented, these connectors are very reliable with their fastenings and connection fixation.

The Micro USB 2.0 connector type “B” has been recognized in its qualities as uniform for universal use for charging all portable devices.

What will happen over time, when all manufacturers begin to produce equipment adapted specifically to such connectors. It probably won't take long to see it.

But this decision was already made in 2011 by all modern manufacturers, although the Micro USB 2.0 type “B” connector is not yet present on all devices.

USB third version type A connectors.

USB 3.0 connectors have greater speed for information transfer due to additional contacts.

With such changes, feedback compatibility is still maintained. Its use has been established in computers and laptops of the latest generation.

USB connectors third version type B.

The third version of USB type “B” connectors are not suitable for connecting USB connectors of the second version.

It is used in the operation of peripheral devices with medium and large productivity.

Micro USB 3.0.

Modern high-speed external drives, as well as SSD-type drives, are basically all equipped with a connector that is characterized by a high speed of information exchange.

It is increasingly occupying a leading position due to the fact that it has very high-quality connections.

The connector is easy to use due to its compact size. Its predecessor is considered to be a Micro USB connector.

Connector pinoutUSB.

The main differences between Micro and Mini USB connectors

At first glance, these connectors are very similar. Indeed, most of the characteristic features of the basic parameters of these species coincide.

But upon closer inspection, you can notice the following differences:

1. The USB Mini connector is larger than the USB Micro connector.
2. The presence of special-purpose latches on the back side of the USB Micro connectors.

Many users have already become convinced that it is most convenient to have not just one type of connector, but several, because different types of devices have different types of USB connectors.

Unfortunately, device manufacturers have not yet come to a single standard, and most likely will not come for a long time, because each type of USB connector has its own purpose.

Just two decades ago, a USB socket was a novelty even for a desktop personal computer. But over time, the usual standard connector turned into a mini, and later a micro one appeared. Today, not a single mobile device can do without this type of interface. It is for this reason that it will not be superfluous to find out what USB and micro-USB ports are, how they are designed and what they are used for.

USB Interface Specification

With the development of computer technology, the problem of prompt transmission of information between devices has become increasingly urgent. Existing serial and parallel port standards could no longer meet the growing needs and were extremely inconvenient to use. The designers were faced with the task of creating universal and, most importantly, easy to use port with high transmission speed. This is what the USB interface - the Universal Serial Bus - is well known to every user today.

The first version of the port - USB 1.0 - did not have a high data transfer speed (1.5 MB/s), but had the properties of versatility and ease of use. The interface was a great fit for working with a wide variety of peripherals and, most importantly, supported hot plugging and plug-and-play. True, the version turned out to be “crude” and worked unstable, so after 2 years another specification was released - USB 1.1. It fixed bugs in USB 1.0 version.

The USB 2.0 protocol retained all the advantages of the previous version and transferred data at speeds of up to 48 MB/s. This version of the specification was already much more useful than its older brother. She could support enough high-speed external drives and ensured the transfer of large amounts of information in a reasonable time. This version is considered the main version to this day - the vast majority of peripherals and mobile devices are produced with the USB 2.0 interface.

The USB 3.0 protocol version, which appeared 10 years ago, has even greater bandwidth (up to 600 MB/s) and is able to serve truly high-speed devices. Like their predecessors, the port is easy to use and has the same architectural structure, which means it allows you to connect external devices “on the fly” (hot plugging) and independently recognizes them. Currently, the ultra-high-speed USB 3.2 protocol is being developed, which will allow devices to exchange information at speeds of up to 2.5 GB/s.

Types of USB connectors

Along with the development of the specification, new types of USB connectors were also developed. This is due to the fact that not only PCs and their peripherals, but also a wide variety of gadgets, including miniature ones, began to be equipped with such an interface. The standard USB connector, originally developed, simply did not fit into the compact housings of mobile devices. Today there are 3 main types of ports:

1. mini USB;
2. micro USB.

Most peripheral devices and gadgets are designed for them.

Three main types of USB connectors today

Regular USB socket

Installed in PCs, laptops and their peripherals - printers, external drives, routers, etc. Universal network adapters have the same sockets.

Standard USB sockets in PC and wall charger

Peripheral devices are equipped with a plug for this type of socket - mice, keyboards, external drives, radio modules, etc. The same plugs can also be seen in adapter cables from one type of connector to another:

USB to micro USB cable

Mini USB interface

This type of interface was developed for miniature devices that require information transfer - a regular socket simply does not fit in them. This standard did not particularly take root due to rather bulky socket design, but even today there are many gadgets that use this type of connector. To pair with other types, as mentioned above, adapter cables are available.

Player with mini-USB and adapter cord for it

Micro USB connector

Today, this type of connector is standard for small-sized devices - almost all gadgets are equipped with it - from phones and tablets to players, navigators and cameras. Despite his compactness and apparent flimsiness, the design, when handled properly, is quite strong, reliable and durable. Following this standard, even devices that absolutely do not need to transmit information are equipped with such sockets - flashlights, radios, wireless headphones, etc. What does a flashlight need a data transfer interface for? That's right, no use. And the socket in such devices is used to supply external power and charge the built-in batteries.

USB ports in ordinary flashlights serve only to charge batteries.

It’s a little strange to see a “cart with a jet engine,” but, you see, it’s convenient - the same flashlight can be charged using a standard cable from any PC, power bank or charger with the appropriate socket.

Special mention should be made of the micro version 3.0 interface. The sockets and plugs in it are slightly different from connectors 1.0 and 2.0:

USB 3.0 cables - regular, mini and micro

Version Compatibility

Since interface specifications appeared almost one after another, the problem of compatibility was quite acute and the designers coped with this task perfectly. All three versions of the specification are fully compatible using a bottom-up protocol. That is, users of old interfaces could connect their gadgets with newer developments. In this case, recognition of the slowest device on the network is performed automatically by the ports and does not require any action from the user.

As for the interface (pinout, shape of sockets and plugs), the first and second versions are completely compatible with each other. Version 3.0 is compatible with the previous ones only in the “regular USB” and “mini USB” types. The micro USB connector of the third version cannot be inserted into the sockets of the previous ones, but vice versa - please.

Using the port for power and charging

In addition to transmitting information, the ports are capable of powering external devices. For this purpose, in all modifications of the sockets there are two separate contacts (pin). This is convenient for working with external devices that do not have their own power source - flash memory, keyboard, radio modules, etc. This same interface property, as mentioned above, is often used in completely non-computer gadgets.

What’s interesting is that, depending on the task, the interface can either supply or receive power to external devices. If you, for example, connect the tablet to a power bank, the device will begin charging its own battery. Connect a flash drive or mouse to the same tablet, and the direction of the current will change - the gadget will supply power to the peripheral device. But if the user does not need to switch the power direction - all this is done automatically - then it is still necessary to know the load capacity of the ports. How much current can a particular socket produce?

According to the specification, the maximum currents for versions 1.0, 2.0 and 3.0 are respectively 500, 500 and 900 mA. However, not all gadgets are able to provide such current, and some can provide more. Everything will depend on the specific device and its operating mode. How to determine whether, for example, a tablet will “pull” an external drive or whether a tablet connected to a PC will charge?

Of course, this information is in the accompanying documentation for every decent device, but you can also use the “poke method”. The USB port is universal and quite “smart”. After connecting the devices, they divide priorities among themselves and figure out what and how much each of them needs.

If the tablet is not able to provide normal current to, say, an external drive, then the peripheral device simply will not turn on. If the PC does not have enough strength to charge an energy-intensive tablet with full current, and the latter does not want to be content with little, then charging will not occur. In any case, you will not be able to burn ports equipped with protection against overload, polarity reversal and short circuit with such experiments.

Theoretically, the interface of the third version of the Samsung smartphone is designed for a current of 900 mA, but, most likely, the gadget itself will not produce that much

Interface cable arrangement

Well, in order for the picture of USB ports to be complete, it is necessary to consider the layout and purpose of the contacts of each type. This information will be useful not only to programmers and DIYers who repair interface cables and replace broken connectors in gadgets, but also to ordinary users who want to know what's what.

Pinout of sockets and plugs

Due to the fact that one of the main tasks before the developers was the possibility of compatibility, the pinout and arrangement of contacts of sockets and plugs of all types, with a few exceptions, differ little from one another.

Wiring diagram of contacts on the plug and socket USB 1.0, 2.0, where: 3 - D+;

4 - ID;

5 - GND;

6 - StdA_SSTX−;

7 - StdA_SSTX+;

8 - GND_DRAIN;

9 - StdA_SSRX−;

10 - StdA_SSRX+.

Color coding of conductors

When unsoldering cables, each of the connector pins is assigned its own color. This helps avoid confusion during manufacturing and makes repairs easier. The standard colors of wires in a USB cable are as follows:

• 1 - red;
• 2 - white;
• 3 - green;
• 4 - black (white for micro 3.0);
• 5 - black;
• 6 - blue;
• 7 - yellow;
• 8 - white;
• 9 - purple;
• 10 - brown.

Cable selection criteria

If you need to connect two devices via USB, but there is no suitable cable, you will have to buy one. But how to choose from all the above variety what you need? The selection criterion is extremely simple - if the cable plugs fit into the device sockets, then you have what you need in your hands. The only thing to remember is that if you use a 2.0 cable to connect devices with 3.0 sockets, then those devices will switch to the 2.0 protocol, but will work great. And one moment. If at least one of the devices does not support the 3.0 protocol, then there is no point in buying a very expensive “three-way” cable - you can get by with the usual one for the second version.

The laptop has version 2.0 sockets, which means that no matter what cable you connect these devices with, they will work using the 2.0 protocol

Well, when buying a cable, ask for an interface cable, not for charging. Some overly smart manufacturers save money and make two-wire USB cables for charging, soldering only the power bus. In appearance, they can be exactly the same as regular interface ones, but they are much cheaper because they do not have wires for transmitting information.

Correct pinout of the plug and socket of the Micro-USB connector for connecting power and charging a mobile phone or tablet.

Pinout diagram

Assignment of micro-USB connector contacts - socket and plug

The USB (Universal Serial Bus) connector is a universal-purpose serial bus, the most common wired method of connecting external devices to a computer. This connector allows you to organize data exchange between a computer and a video camera, card reader, MP3 player, external hard drive, or smartphone.

Charging the battery via Micro USB

In addition, it supplies a 5-volt power supply to charge the battery of wearable gadgets. Since almost all modern lithium batteries have an operating voltage of 3.7 V, the 5 V supplied via Micro-USB is excellent for replenishing energy. True, not directly to the battery, but through the charger converter.

I’m glad that the connector pinout is the same for all smartphone manufacturers - Samsung, LG, Huaway and others. Thus, a 220 V charger-adapter from one phone is most often suitable for charging another without changing the pinout.

• The main advantage of the Micro-USB connector over other types is the ability to connect Plug&Play devices without the need to restart the computer or manually install drivers. Devices can be connected while the computer is running and disconnected without having to press any buttons.

Difference between Micro-USB A and B

Please note: The micro connector contains 5 pins. Type B connectors do not use the fourth pin. In type “A” connectors, the fourth contact is connected to GND (minus). And for GND - the fifth contact.