he USB Type-C Specification 1.0 was published by the USB Implementers Forum (USB-IF) and was finalized in August 2014.It was developed at roughly the same time as the USB 3.1 specification. In July 2016, it was adopted by the IEC as "IEC 62680-1-3"A device with a Type-C connector does not necessarily implement USB 3.1, USB Power Delivery, or any Alternate Mode: the Type C connector is common to several technologies while mandating only a few of them.
USB 3.2, released in September 2017, replaces the USB 3.1 standard. It preserves existing USB 3.1 SuperSpeed and SuperSpeed+ data modes and introduces two new SuperSpeed+ transfer modes over the USB-C connector using two-lane operation, with data rates of 10 and 20 Gbit/s (1250 and 2500 MB/s)
现在每个厂商都说自己产品有快充,真正意义的快充是需要充电器、手机、线材三者匹配,才能实现快充,对于高通QC、MTK PE等传统高压快充,对线材的要求最低,正规的普通usb数据线即可,对于OPPO、VIVO和华为等大电流快充,对线材的需求稍高,需要能过大电流线材,所谓的大电流最简单的方法就是加大导体直径降低电阻即可达成,没有啥技术含量.
真正的type-c快充线是指支持USB-PD快充协议的线材,这种线材两端都为type-c接口,就是我们所描述的满PIN线材,具体参照:Type-C技术参数集锦
PD快充协议本身是type-c标准的一部分,支持给手机、平板、笔记本充电,支持双向供电,大有取代和统一快充标准之势。其电压电流功率组合非常多(5-20v 0-5A 18W 30W 45W 65W 100W),握手通信过程远复杂于其他快充标准,涉及到一定的数据通信.
因此仅靠普通usb接口无法实现,必须采用type-c对type-c的数据线才能实现pd快充。(Type-c是24pin接口,有专门用于快充通信的引脚。而普通USB 3.0的接口只有9pin,没有专用于快充的引脚,只能复用引脚).参照下图的引用描述
ReceptaclesThe receptacle features four power and four ground pins, two differential pairs for high-speed USB data (though they are connected together on devices), four shielded differential pairs for Enhanced SuperSpeed data (two transmit and two receive pairs), two Sideband Use (SBU) pins, and two Configuration Channel (CC) pins
Plugs,具体参照:Type-C 技术参数图解发布
The male connector (plug) has only one high-speed differential pair, and one of the CC pins is replaced by VCONN, to power electronics in the cable, and the other is used to actually carry the Configuration Channel signals. These signals are used to determine the orientation of the cable, as well as to carry USB Power Deliverycommunications.
Alternate Mode partner specifications
As of 2018, five system-defined Alternate Mode partner specifications exist. Additionally, vendors may support proprietary modes for use in dock solutions. Alternate Modes are optional; USB-C features and devices are not required to support any specific Alternate Mode. The USB Implementers Forum is working with its Alternate Mode partners to make sure that ports are properly labelled with respective logos