Fast Charge Technology: Introduction to USB Power Delivery and Quick Charge™

The performance of mobile phones, computers and other technological products is getting stronger, the screen area is getting bigger and bigger, and the power consumption is also increasing. How to realize fast charging is a topic of concern to users. However, in the user experience, the following phenomena have become a problem for consumers:

The mobile phone has a fast charging function, but why is the charging speed still slow?

There are hidden dangers to fast charging safety? The charging exploded into a panic.

Charging while sliding the phone, the phone gets hot and panic? !


The quality of products on the market is uneven. If consumers use a charger that does not meet the specifications, or use a charger that does not meet the standard, or use a low-quality cable, the mobile phone will not only fail to achieve the fast charging function, but it will also produce safety. Hidden dangers. What do you know about fast charging?


Fast charging principle:

In electricity, the voltage (Volt, V) multiplied by the current (Ampere, A) can get the power (Watt, W). The higher the charging wattage, the shorter the time required for charging. The current fast charging technology can be implemented in the following three ways:

1. High voltage and low current mode: increase the voltage and increase the charging power

2. Low voltage and high current mode: increase the current and strengthen the charging power

3. High voltage and high current mode: increase the voltage and increase the current





Simply put, fast charging is to effectively increase the charging speed of the product and shorten the charging time within a safe load range. The fast charging technologies currently on the market include Quick Charge™ (QC) launched by Qualcomm and USB Power Delivery (PD) defined by the USB Developer Forum.



»What is USB Power Delivery?

USB Power Delivery (USB PD) is a USB power supply expansion standard that uses a USB (Universal Serial Bus) cable to support up to 100W power supply and reception. In the past, the maximum USB power supply was USB 2.0 (2.5W), USB 3.0 (4.5W), and BC 1.2 version (7.5W). Now it has jumped to 100W for power supply and reception. Therefore, devices such as laptops and tablet computers that could not be supported in the past are also available. Power can be supplied and received, and the equipment that can be supported has been greatly expanded.

USB PD uses a USB Type-C® connector, which can supply power while transferring data through USB, covering mobile phones, cameras, power banks, tablets, laptops, monitors, etc., charging and data transmission can be easily done with one cable. It also supports Alternate Mote mode, which can handle video signals. You can use a USB port for data transmission, power supply and reception, and video signal transmission, thus building a simple and convenient environment.


»USB Power Delivery (USB PD) technology

The USB Power Delivery (USB PD) 1.0 specification has five levels of power supply settings (Profile 1~5):

Profile 1 (provides 5V@2A, 10W power supply; applicable to various portable devices such as mobile phones)

Profile 2 (provide 5V@2A, 12V@1.5A, 10~18W power supply; suitable for tablet computers or external storage devices)

Profile 3 (provide 5V@2A, 12V@3A 36W power supply; suitable for ultra-extreme laptops and other devices)

Profile 4 (provides 5V@2A, 12/20V@3A 60W power supply; the maximum power supply specification supported by microUSB, applicable to All in One computers)

Profile 5 (provides 5V@2A, 12V@5A, 20V@5A 100W power supply; used for standard A/B and USB Type-C® connectors, suitable for LCD monitors and flat-screen TVs)

USB PD 1.0 supports four voltages 5V, 9V, 15V, 20V, up to 100W, and is downward compatible with USB 3.2/2.0, BC 1.2/1.1/1.0, and has 5 profiles. USB PD 2.0 can use Type-A, Tyep-B and Type-C interfaces. To USB PD 3.0, only USB Type-C® interface can be used, and PPS (Programmable Power Supply) is added.



»USB PD 2.0 vs. USB PD 3.0 


»What is QC fast charge?

Quick Charge™ (QC) is a fast charging technology developed by Qualcomm. As long as there is an Android phone equipped with its Snapdragon system chip, its fast charging technology can be used. In addition to supporting a variety of mobile phones with Snapdragon processors, it also supports some other brands of processors. The historical version of QC fast charging technology is as follows: QC 1.0 supports 10W and up; QC 2.0 supports 15W and up; QC 3.0 supports 18W and up; QC 3+ supports 18W and up; QC 4 supports 18W(A)/27W(B) and up; QC 4+ supports 18W (A)/27W (B) and up; QC 5 supports 45W and up.


In 2020, Qualcomm launched the commercial fast charging technology Quick Charge™ 5 (QC 5), which can support fast charging chips with charging power greater than 100W for Android smartphones. Its efficiency is 70% higher than the previous generation, and the charging speed is 4 times faster. It can charge the device from 0% to 50% in 5 minutes. At the same time, it adopts Qualcomm's charging power smart identification adapter technology, which can convert at the highest power The transmission efficiency ensures charging safety and prolongs the battery life of the device.

In addition, QC 5 is not only compatible with the previous QC 4+, QC 4, QC 3 and QC 2, but also continues QC4, can be applied to USB-PD and Type-C technologies, and is compatible with USB Type- C protocol and other industry standards, so it can be expanded to other devices.


» QC4+ vs. QC5