USB PD--Mission and glory

Publish Date:2016-10-27 | Hits: | 字号:

       A couple of years ago, I was a bit crazy about facing a host of adapters on the desktop. First, these adapters create a messy home environment and inconvenience. Second, the occasional damage to a device adapter, you will find it difficult to buy the right alternatives. Third, these adapters will cause countless e-waste, including plastic, heavy metal pollution. As the only person at home who knows electricity, I have to bear the inconvenience caused by the use of various complaints, and struggling to explain why this does not fit that. So, one day, the other half said to me, you put all of these adapters into a unified multi-functional bar, let the appliance to tell the adapter what the output on the line. I think this idea is very valuable to write a patent number: 201210007717.X patents, and submitted to the Patent Office for examination. Time passed quickly, in 2014, I first read TYPE-C and USB PD specification. I almost instantly understand that they carry the mission. TYPE-C and USB PD launch, will fundamentally solve our lives, involving the chaotic situation of power supply of electronic products. How does it work? Let's see:

The first step, the adapter is established, will be broadcast through the CC line, tell the other side of the connection, the adapter can provide the number of voltage and the corresponding current.


PC communication waveform of original adapter of Macbook

PC communication waveform for Google native adapter

       The second step, with the electrical power adapter in the learned capacity, select one of the most suitable for their own power supply, and send the request to the adapter data packets.

Request packets sent by Macbook

       The third step, the adapter based on the choice of appliances to assess their own ability, send "accept" command.

The adapter sends the ACCEPT PD communication packet

       In step 4, the adapter performs an internal voltage conversion and sends a "power-ready" packet to the consumer。

The adapter sends power to switch PD communication packets

       In step 5, the adapter applies a new supply voltage to VBUS after negotiation.

       If only a power management. Then the PD communication to this has completed the task of voltage switching. However, if the power supplier is not just an adapter, but a HUB, or even support the HDMI output of the HUB, then, PD will also need to negotiate more to achieve the system defaults to other functions.

       Among them, including the data transmission role conversion, VDM communication, DP signal configuration.


Apple original USB DOCK sent DR_SWAP packet

Apple original USB DOCK sent DP Configure packets

Apple's original USB DOCK Send Entry Mode packet to Macbook output DP signal

Apple original USB DOCK sent unstruct VDM data packets are private communications

       These waveforms are from the actual PD communication process monitoring, using the LEADER in the industry's first mass production of PD logic analyzer-LDRPD01.

The LDR PD01 analyzer monitors the communication between DOCK and MACBOOK

The LDR PD01 analyzer monitors PD communication for the GOOGLE Chromebook charging process

       This monitoring system can provide a valuable reference for the practitioners of USB PD-related products and accurately grasp the error information of the PD communication process. If necessary, welcomed the WeChat 13510191269.

       And QC2.0 difference: First, from the name to see a glimpse of the clue, PD is Power Delivery, concerned about two or more devices, or even a smart grid based on USB interface, power transmission process, power transmission can be Dual-direction, and even networking, you can have a system-level power supply strategy. The QC is the Quick Charge only concerned about the rapid charging problem, power transmission is unidirectional, do not have the power network capacity, does not support other than the power supply other functions.


QC2.0 is concerned with a charging device and a charging device

USB PD solves the problem of balancing a power transmission network

       In summary, we can see, USB PD not only for the consumer electronics has brought a variety of interface applications, but also carries the future of consumer electronics and some household appliances, power management intelligence of the mission, will be able to better solve the current power supply Way of confusion, a variety of adapters and cable serious waste of social resources, pollution of the natural environment. Shenzhen Le Deli Technology Co., Ltd., is committed to USB TYPE-C interface and USB PD related application technology development, has launched support TYPE-C interface chip LDR6013, and support USB PD chip LDR6021, actively cooperate with USB-IF And jointly promote this major reform in favor of human society.