USB Type a/b/c basic knowledge and different versions

Since Apple recently used a single data interface USB Type C on a new MacBook, the discussion about USB interfaces has become lively. In Apple's new MacBook, the entire fuselage has only one data interface (except the power connector) USB Type C, which makes people wonder if a single interface can meet high speed and stable audio and video data transmission. To answer this question, we have to understand the USB Type C interface, here is a small part of the conclusion: USB Type C is able to do without loss of speed and transmission quality for almost all specifications of the data transmission (need to use the transfer interface), So today we would like to take this opportunity to introduce some basic knowledge about USB2.0, USB3.0, USB Type C, etc.

USB is an acronym for Universal Serial Bus, a bus architecture developed by Intel Corporation, making it easy to add serial devices to your computer. Simply plug the device into the computer's USB port and the system is automatically identified and configured. According to the development of the Times, USB interface standard experienced a generation of USB, second-generation USB 2.0 and third generation USB 3.0, this is from the time dimension, but each generation of USB interface for different devices and subdivided specific models. This is very good understanding, such as printers and computers for data transmission requirements are not the same, you want to print the most is text or image information, computer data transmission Type a lot, since how we can for the characteristics of the printer, from the USB interface to subdivide a class to the printer to use, This will enable better transmission efficiency. The basic truth is that, each generation of USB interface according to the characteristics of the supported devices are subdivided into USB Type A/b/c/mini/micro, about these kinds of interfaces suitable for which equipment small series after again, the following small series on just mentioned a few interface specifications specifically introduced under:

　　The meaning of USB 1.0/2.0/3.0

　　USB 1.0

The USB specification was first introduced in 1995 by a usbif (USB implement Forum) consisting of seven companies such as Intel, IBM, Compaq, Microsoft, NEC, Digital, North Telecom, etc. Usbif in January 1996 formally proposed the USB1.0 specification, the frequency width is 1.5Mbps. But because at that time support USB peripheral device is poor, so the host board is not very USB port design directly on the motherboard.

　　USB 2.0

USB2.0 technical specifications are by Compaq, Hewlett Packard, Intel, Lucent, Microsoft, NEC, Philips jointly developed, published, the specification of peripheral data transmission speed to 480Mbps, is a USB 1.1 Device 40 times times! The USB 2.0 standard developed in 2000 is truly USB 2.0, a high-speed (high-speed) version known as USB 2.0, with theoretical transmission speeds of Mbps.

　　USB 3.0

USB 3.0 is the latest USB specification, initiated by companies such as Intel, USB3.0 's maximum transmission bandwidth of up to 5.0Gbps (640mb/s), and USB3.0 introduces Full-duplex data transfer. 5 lines of 2 are used to send data, the other 2 to receive data, and 1 are ground. In other words, USB 3.0 can be read and write synchronously at full speed.

　　USB Type A/b/c/mini/micro features of each series

USB Type A (left) and USB type B (right)

USB Type A: This standard is generally applicable to PC PCs and is applied to the widest range of interface standards

USB Type B: Generally used for 3.5-inch mobile hard disk, as well as printers, monitors and other connections

Mini-usb

Mini USB Type A (left) and mini USB type B (right)

Commonly used in digital cameras, digital cameras, measuring instruments and mobile hard drives, such as mobile devices

Micro USB

Mini USB Interface for mobile devices

In the USB2.0 era, the Micro USB port appeared, a portable version of the USB 2.0 standard, the next-generation specification for mini USB, smaller than the mini USB interface used by earlier parts of the phone. This interface is our most common interface, our phone's charging interface is the micro USB interface.

USB Type C:USB Type C This interface name appears after the USB 3.1 era, with a brighter design, faster transmission speed (up to 10Gbps), and more powerful power transmission (up to 100W). Type-c dual-sided pluggable interface is the largest feature of the support of the USB interface double-sided insertion, mainly for the more lightweight, more slender equipment (the future may be unified mobile phone plate interface, replace the micro USB interface).

Now the most common USB Type C interface, do not distinguish between positive and negative inserts

In conclusion, USB Type-c has the following features:

1. Maximum data transmission speed of 10gbit/seconds, but also USB 3.1 standard;

The size of the socket end of the 2.type-c interface is about 8.3mmx2.5mm slim design;

3. Support from both sides can be inserted "positive and negative plug" function, can withstand 10,000 times repeatedly plug and pull;

4. The standard specification connector with the TYPE-C connector can pass 3 A current, while also supporting "USB PD" exceeding the existing USB power supply capability to provide maximum 100W of power.

USB Type C Interface (left) Apple Lighting line Interface (middle) and micro USB interface (right) contrast

Currently, common electronic devices that support USB Type C interfaces include: Nokia N1 tablet, video phone and Apple MacBook.

Please note that for USB type A/b/c/mini/micro These are not all owned by each generation USB, in the USB 1.0/USB 2.0 era there is no USB type C interface. In the current smartphone era, we use the Micro-usb interface which is based on USB 2.0, that is, the USB data cable interface of mobile phone. USB Type C is the most promising development in the next generation of USB, and as Apple takes the lead, it is believed that more and more vendors will follow up.