The differences of USB PD3.0 and USB PD2.0
As for the terms of protocol, PD2.0 is a subset of PD3.0, that is to say, PD3.0 is naturally compatible with PD2.0.From the hardware level, the link layer and physical layer of PD3.0 and PD2.0 are fully compatible, that is to say, when the product is upgraded, there is no need to change the hardware, only the online software upgrade.
The changes of PD3.0 relative to PD2.0 are mainly in 3 aspects:
1. Added a more detailed description of the device's built-in battery characteristics. It can make the two parties connected and understand the power status of the other party, so as to coordinate the power supply strategy of both parties.
2. Added the function of device hardware and software version identification and software update through PD communication. It can make the device compatibility more excellent. All TYPE-C manufacturers can publish their latest firmware versions on the Internet, so that they can update non-networked peripheral accessories in time through PCs and mobile phones.
3. Added digital certificate and digital signature functions. This allows all TYPE-C products to obtain a digital certificate issued by the USB-IF organization using a private key in order to be unimpeded. Products without certificates may not be accepted by TYPE-C products of other manufacturers.
The difference between PD3.0 and PD2.0 mainly lies in:
1. The difference in appearance
(1) USB 3.0: Observe the USB (self) slot and USB slot on the computer, the color of the middle plastic board is blue is USB3.0
(2) USB 2.0: Observe the USB (self) slot and USB slot on the computer. The color of the middle plastic board is black is USB2.0
2. Differences in compatibility
(1) USB 3.0: USB 3.0 has a backward compatible standard, compatible with USB1.1 and USB2.0 standards, with easy-to-use traditional USB technology and plug-and-play functions.
(2) USB 2.0: The USB (Universal Serial Bus 2.0) interface has a faster transmission speed, supports hot swapping and connects multiple devices. Can be backward compatible with USB1.1.
3. The difference in transmission speed
(1) The USB 3.0 specification has been optimized to achieve lower energy consumption and higher protocol efficiency. The USB 3.0 port and cable are backward compatible and support future fiber optic transmission.
(2) The actual transmission rate of the USB3.0 super high-speed interface is about 3.2Gbps (ie 320MB/S). The theoretical maximum rate is 5.0Gbps (ie 500MB/S). The USB2.0 transmission speed can reach 480Mbps.