With the increase in the functionality of smart phones, power consumption has become faster and faster, and people have become more hungry for the improvement of the charging efficiency of mobile phones and the reduction of power consumption. With the long-awaited USB Type-C standard released, the USB-PD protocol has also entered the public eye. This new charging protocol has overturned people’s perception of USB charging inefficiency.
It is said that the USB-PD protocol can carry 3A or 5A current, and the transmission power can reach 100W. At the same time, the interface defines a proprietary channel for power transmission protocol communication, which can achieve intelligent self-adaptation between charging and receiving devices. Charge adjustment to improve charging efficiency.
So, what is USB-PD?
“USB Power Delivery Specification (USB PD)” is a standard that can supply 100W of power using a USB interface, and is designed to provide users with a more powerful power charging solution. When USB 2.0 is only used for the drive of a portable terminal and the charging of a built-in rechargeable battery, the “USB Battery Charging” standard increases the power supply, but the power supply is only 7.5W.
At present, the USB PD standard is divided into 10W, 18W, 36W, 60W and 100W five-level “Specifications”. The voltage is 5V, 12V and 20V, and the current is 1.5A, 2A, 3A and 5A. This flexible configuration allows various electronic devices. It can meet the power supply requirements through a USB cable. It can not only supply power to mobile devices, but also directly supply power to notebooks and monitors. What’s more, it can achieve two-way charging, which means that two computers can be connected by USB cable. Charge each other.
USB-IF (Common Interface Industry Association) has established the USB PD standard, 7.5W is still only powered by 5V, but 10W, 18W began to introduce 12V outside 5V, 60W and 100W will introduce 20V. Although the power supply is amplified to 100W, there is still a difference in cable. The standard USB cable that has been used for a long time can supply 100W, but for the Micro-USB commonly used in mobile devices, the connector is small and physically limited. Under, only 60W can be powered, not 100W.
Similarly, the USB-IF new C-type connector, which is a small connector for mobile, can not reach 100W power supply, and its limit is 60W.In addition, the unofficial Powered USB estimation will gradually fade out, and only a few applications will continue to adopt. Once the USB power supply capability can reach 60W or 100W, the next step may be to implement a printer, a scanner, a desktop monitor, etc., which can be changed to USB power supply, which means changing notebooks, changing printers, etc. in the future. Instead of discarding the transformer, you can use it to reduce e-waste.
In fact, if you look closely at this table, it is not difficult to find that this allocation can actually be divided into three types. Among them, 10W only provides the output of 5V@2A, which is to increase the current current upwards. This is the most basic USB PD port. In the future, 18W and 36W belong to one grade. The USB port not only provides 5V but also provides 12V power supply, which can supply power for some external HDD, vehicle power supply and other equipment. The third type is to provide a 5V/12V/20V USB port. This type can provide power for external HDDs, on-board devices, and power for notebooks and external monitors.
It is worth mentioning that, whether it is the most common USB PD port, the wire must be re-applied. In addition, it is also necessary to note that the connector that supports the 100W output only has the Standard A and Standard B standard specifications, and the Micro can only support 60W.
USB-PD system design level needs to advance
USB-PD breaks the existing charging voltage limit, and notebook and tablet manufacturers can design different power supply solutions according to product requirements. However, to introduce the next-generation USB-PD specification for electronic devices, new cables and connectors must be used and tested for related security and protocols. Mainly considering the USB upgrade to medium and high power charging, the traditional cable can not fully meet the voltage/current rating of the USB-PD, and it will have a certain degree of influence on the internal circuit and user safety of the device, so the future USB cable Both the connector and the connector must be equipped with an ID pin to enhance the circuit protection function.
In addition, the USB-PD connector must be backward compatible to support existing USB products. The USB PD specification that supports power delivery will be set as the next generation of new standards. This technology is likely to change the way electronic products are used, because the device will no longer need to be connected to a separate power supply. USB can provide data access to the device. Power supply up to 100W, which is 10 times stronger than today’s USB power supply, and more efficient in the process of power transmission conversion, reducing energy waste caused by heat.
For power supply solution providers, the technical challenge of developing USB-PD also includes the selection of peripheral components, and must consider the two aspects of power supply and consumption, in response to 5, 12 and 20 volts or different current specifications, Multi-software hardware development resources to improve the existing USB interface 5 volt VBus power line, and increase the support voltage level to 12 or 20 volts.
USB PD not only has industrial significance, but also has several social significance. USB PD means further globalization. In the past, different analog TV standards have been adopted in the world, such as NTSC US regulations, PAL European regulations, etc., connectors also have US RCA terminals, Japanese S terminals, etc., which are the differences in the national portal, and now gradually OTT, Internet Network specifications and HDMI connectors are unified. Similarly, power sockets of different frequencies, different voltages and different connectors are used all over the world. These differences make the terminal users have to take the universal adapter when going abroad. If the transformer is damaged or stolen, it can only be found in the original factory. Purchase.
Summary: The emergence of USB PD will have the opportunity to unify applications below 100W, and USB power has gradually integrated into life. In the future, with laptops, countries no longer need to bring transformers, as long as they have a USB cable, they can even have a built-in shrinkable USB cable, which greatly enhances convenience.