Since the official release of USB1.0 in January 1996 (USB3.2 was released in September 2017), USB has gone through 21 years. In these 21 years, the USB Association (USB Implementers Forum, USB-IF) Many interfaces are proposed: Type A, Type A SuperSpeed, Type B, Type B SuperSpeed, Mini-A, Mini-B, Micro-A, Micro-B, Micro-B SuperSpeed, Type C, etc., Sinodec Inudustrial Co. , ltd. provides all USB cable production and wholesale, and also provides custom usb cable. Now, with its own powerful functions, USB Type-C has begun to increase the application scenarios year by year, from mobile phones and tablets to automotive applications, this interface will be active in the future It affects all aspects of our daily life, mentioning type C, it is really not the same as its predecessors A and B: because it has its own independent, self-evolving specification file-USB Type-C Specification (issued in 2014 8 Monthly version 1.0, version 1.3 was released in July 2017). The predecessors have no such treatment. They all depend on the specific USB specifications (USB 1.0, USB 1.1, USB 2.0, etc.). In the electronics industry, Type-C exists in the minds of every engineering designer. In the meantime, due to the intensified market competition, various specifications not specified by the USB Association are also seizing various application markets to avoid citation errors. We will organize the USB Association specifications and share them with everyone.
Introduction of USB interface
The USB interface is mainly composed of a socket (Receptacle), a plug (Plug) and a cable (Cable), and then combined according to various association specifications in the USB Association, A-to-A, B-to-B, A- to-MicroA, etc., but our protagonist USB Type C defines a new interface form. In addition, in order to be compatible with the old interface and some special functions, it defines different forms of sockets, plugs, cables, etc., mainly including the following:
Two Type-C sockets are defined
Full-featured Type-C socket can be used for platforms and devices that support USB2.0, USB3.1, and other features.
The USB 2.0 Type-C socket can only be used on platforms and devices that support USB 2.0.
3 types of Type-C plugs are defined
Full-featured Type-C plug can be used on platforms and devices that support USB2.0, USB3.1, and other features.
The USB 2.0 Type-C plug can only be used on platforms and devices that support USB 2.0.
USB Type-C Power-Only plug, used on devices that only need power supply (such as charger)
Three standard Type-C cables are defined
Full-featured Type-C cable with full-featured Type-C plugs on both ends.
USB 2.0 Type-C cable with USB 2.0 Type-C plugs on both ends.
A cable with a Type-C plug (full-featured Type-C plug or USB 2.0 Type-C plug) on only one end
Cables or adapters defined for compatibility with old equipment
A cable with a fully functional Type-C plug on one end and a USB 3.1 Type-A plug on the other end.
A cable with a USB 2.0 Type-C plug on one end and a USB 2.0 Type-A plug on the other end.
A cable with a fully functional Type-C plug on one end and a USB 3.1 Type-B plug on the other end.
A cable with a USB 2.0 Type-C plug on one end and a USB 2.0 Type-B plug on the other end.
A cable with a USB 2.0 Type-C plug on one end and a USB 2.0 Mini-B plug on the other end.
A cable with a fully functional Type-C plug on one end and a USB 3.1 Micro-B plug on the other end.
A cable with a USB 2.0 Type-C plug on one end and a USB 2.0 Micro-B plug on the other end
An adapter with a fully functional Type-C plug on one end and a USB 3.1 Type-A socket on the other end.
An adapter with a USB 2.0 Type-C plug on one end and a USB 2.0 Micro-B socket on the other end
After reading the above combination types, you should be able to feel how complicated the previous USB interface specification is.
Definition of USB C PIN and its signal
The USB Type-C interface has 24 pins. The socket and plug have a little difference in the definition of pin signals, as follows:
The above signals can be divided into 5 categories according to function:
Category 1: Power related signals, including
a) VBUS, the bus power of the USB cable (which is consistent with our usual VBUS).
b) VCONN (this signal is only available on the plug), used to supply power to the plug (thus it can be speculated that some plugs may have circuits).
c) GND, ground
The second type: USB 2.0 data cable, D + / D-, they have only one pair at the plug end, which is consistent with the old USB 2.0 specification. But in order to support positive and negative random insertion. Two groups are defined on the socket side, so that the socket side can perform appropriate mapping according to the actual situation.
The third category: USB3.1 data cable, TX +/- and RX +/-, used for high-speed data transmission. There are two groups of plugs and sockets, which are used to support the positive and negative random insertion.
The fourth category: the signal used for Configuration, for the plug, there is only one CC, for the socket,