What is the USB?

We explain what USB is and what this universal connection method is for. In addition, its various standards and types of connectors.

1. What is the USB?

In computer science , the terms USB (acronym for  Universal Serial Bus , that is, Universal Serial Bus ) or BUS refer to a standard of connection and electrical and data transmission , between computers, peripheral devices and other electronic devices.

This system consists of a communications bus guided by universal serial protocols , cables and connectors, which emerged as a way to universalize the connection of the devices to the different computer models .

It should be clarified that a bus, in computational architecture, refers to a digital data transmission  system between computers and their components, manufactured in a printed circuit with resistors and capacitors , and commonly used in today’s computing.

The USB emerged in 1996 in its version 1.0 , as an initiative of Intel, Microsoft , IBM, Compaq, DEC, NEC and Nortel, then incompatible with each other, by standardizing the connection ports of their products.

Two years later, the 1.1 specification was already in mass use, and since then its use became the norm, replacing connectors such as the serial port, parallel port, game port, among others.

Currently most peripherals use USB connectors: pointers, flash drives, keyboards, joysticks, scanners, cameras, speakers, cell phones, etc.
This offers endless advantages, beyond extreme compatibility: peripherals can be connected at any time and recognized instantly, allows the joint transmission of data and electricity , and also allows transmission speeds of up to 1250 Mbps (in its standard valid).

2. What is the USB for?

In principle, USB plays an important role in today’s hypercomputed world: to serve as a universal method of connection , thus eliminating the need for adapter devices, attending to the types of connector of a peripheral, and even allowing rapid transit of the information between different types of electronic system.

In addition, the USB allows you to charge the battery of electronic devices , connecting them to a computer, whether or not connected to a power line.

3. USB standards

The  type of connector for these functions is called  USB standard , which has evolved over time, increasing its capabilities and adapting to the needs of the new computer hardware . The standards to date are:

• Standard 1.0 . The initial, low-speed model, which failed to become popular the year of its launch. In its full version (1.1) it offers a transfer rate of up to 1.5 mbps.
• 2 Standard . 0 . High-speed calls, increased the transfer rate to 480 mbps, using two pairs of cable lines: two for electricity and two for data.
• Standard 3 . 0 . Considered of super high speed, it allows to reach 600 mbps, since it includes five additional contacts, discarding the traditional optical fiber although it will be compatible with the previous standards. Its most updated version (3.2) was announced in July 2017 and is expected to reach much higher speeds in 2019.

4. USB connectors

Within the same USB standard, several types and sizes of connectors are contemplated, that is, cable terminations. Some of its characteristics, however, vary, in order to vary the polarity and avoid electrical surges.

• T ipo A . The most frequent arrangement, present in removable memory units (flash), is usually of medium size, flat, and is frequent in hubs and many peripherals.
• Type B . Square and elongated, they are usually used by large devices, such as printers or scanners.
• M ini -USB . Often used in digital cameras and other devices, it almost always consists of a type B connector.
• M icro -USB . Present in most smartphones, in its 1.1 / 2.0 and 3.0 variants, it is the smallest version that exists.