In 1996, Intel, Microsoft, IBM and other companies jointly designed and launched the USB standard.
In the past 20 years, the performance and functions of USB have experienced tremendous improvements. The transmission rate of USB has increased from 1.5Mbps of USB1.0 to 10Gbps of USB3.1, and then to the current 40Gbps of USB4.0.
Classification of USB
According to the interface form, USB can be divided into three categories: Type-A, Type-B and Type-C. Type-A and Type-B have two sub-types: Micro and Mini.
In the era of USB1.0 to 2.0, Type-A and Type-B occupied the mainstream market.
In the era of USB3.0 and 3.1, Type-C was launched. It was first used on Nokia N1 tablets and Chromebook Pixel. Apple computers began to use it in 2015, which quickly promoted the popularization of TYPE-C. At present, TYPE-C has become the mainstream signal interface standard, and its application fields span smartphones, laptops, tablets, wearable devices, cars, etc.
The emergence of USB3.1 symbolizes a leap-forward upgrade in high-speed transmission and the realization of power transmission technology.
Advantages of Type-C (compared to TYPE-A/B)
- Compatibility: It can expand a variety of audio and video
transmission interfaces, including DP, Thunderbolt, VGA, HDMI, etc.,
and is also backward compatible; - High-speed transmission: The USB4.0 (released in 2019) standard has
a maximum speed of up to 40Gbps, which is twice the transmission
rate of USB3.2; - Supports dual-screen 4K high-definition image transmission;
- Supports two-way power transmission and fast charging: It can
provide a power output capacity of up to 100W; - Small and thin, durable and convenient: The bottom size of the
interface socket is only 8.3mm×2.5mm, which is one-third of the size
of the Type-A interface. At the same time, it can withstand about
10,000 repeated plug-ins and unplugs.
The relationship between USB and Thunderbolt
The Thunderbolt protocol was released by Intel and integrates two communication protocols: PCI Express data transmission and Display Port video transmission.
In 2015/2020, Intel successively released Thunderbolt 3.0/Thunderbolt 4.0, both of which adopted the Type-C interface with a transmission speed of up to 40Gbps.
The latest USB4.0 is compatible with the Thunderbolt protocol, and supports USB PD protocol, USB 3.X protocol and DP protocol at the same time, and only supports Type-C interface.
Judging from the latest standards, the Type-C interface is already a general trend, and it is also a standard configuration for newly launched smart devices to be equipped with Type-C.