Looking back more than a decade ago, 5W (5V/1A) charging power was standard on most mobile phones, and "charging overnight" was the norm. And today, 240W fast charging has been achieved, the phone can be fully charged in 10 minutes, and the laptop can also get enough power through the universal interface. Behind this speed revolution is a series of breakthroughs in technical problems and the continuous evolution of fast charging protocols.

1. The beginning of chaos: the era of 5W "slow charging"

• Technical background: Early USB-A port standard outputs were 5V/0.5A (2.5W) and 5V/1A (5W). There are no complex "protocols" at this time, and charging is completely dependent on the underlying USB standard, which is slow.

2. The first breakthrough: increase voltage - QC 2.0/3.0 era

• Core idea: When the upper limit of the current remains unchanged, increase the power by increasing the voltage. P (Power) = V (Voltage) x I (Current).

• Technical representative: Qualcomm Quick Charge 2.0/3.0.

• Breakthrough Points:

• The voltage is increased from 5V to 9V, 12V or even 20V, and the power reaches more than 18W.

• Challenge: The mobile phone battery is subjected to ~4.4V voltage, and the high-voltage power needs to be converted through the step-down circuit inside the mobile phone, and the energy loss during the conversion process is released in the form of heat, resulting in serious heat when the mobile phone is charged.

3. The second breakthrough: increasing the current - the VOOC/Dash Charge era

• Core idea: When the voltage remains unchanged at 5V, greatly increase the current to increase the power.

• Technical representatives: OPPO VOOC, OnePlus Dash Charge.

• Breakthrough Points:

• Increase the current from traditional 2A to 4A, 5A, or even 6A, and the power reaches 20W-30W.

• Challenges and Solutions:

• Challenge: High currents generate significant losses and heat generation on common Micro-USB interfaces and cables.

• Solution: Using customized interfaces, thickened cables, and placing the main step-down process in the wall adapter, the heating of the mobile phone is significantly reduced, realizing "fast charging while playing".

4. The third breakthrough: high voltage + high current and dynamic regulation - PD 2.0/3.0 era

• Core idea: Integrate the advantages of the first two, and introduce an intelligent dynamic adjustment mechanism to pursue versatility.

• Technical Representative: USB Power Delivery (PD).

• Breakthrough Points:

1. Versatility: The goal is to unify the charging standards for mobile phones, tablets, and laptops.

2. Flexibility: Supports multiple fixed voltage levels such as 5V, 9V, 12V, 20V, etc., and intelligently negotiates through the CC cable of the USB-C interface to provide up to 100W (20V/5A) of power for different devices.

3. PPS (Programmable Power Supply): A revolutionary technology introduced in the PD 3.0 protocol. It allows for fine-tuning voltage in 20mV gears, enabling fine power regulation at the level of 10W. This results in more efficient charging, less heat generation, and better matching with subsequent charge pump technology.

5. Key technical support: charge pump and GaN

Protocols alone are not enough, and implementing them requires breakthroughs in hardware technology.

• Charge Pump Technology:

• This is a "black technology" for efficient step-down. It converts voltage through capacitor arrays, with an efficiency of more than 98%, which is far from 80-90% of traditional step-down circuits.

• It perfectly solves the problem of hot mobile phones in high-voltage solutions, so that the conversion of "high voltage, low current" to "low voltage, high current" to charge the battery is minimal, and the heat loss is minimized. This is the cornerstone of realizing fast charging of 100-watt mobile phones.

• GaN technology:

• Traditional silicon-based adapters are bulky when it comes to achieving high power. As a third-generation semiconductor, GaN allows adapters to operate at higher frequencies, resulting in significantly smaller internal transformers, capacitors, and other components.

• GaN technology makes high-power fast charging adapters miniaturized and portable, solving the contradiction between "high power and portability".

6. Ultimate form: towards 240W - PD 3.1 era

• Core breakthrough: Increase the maximum power of the PD protocol from 100W to 240W.

• How to do it:

• On the basis of the original 100W specification (up to 20V), three extended voltage levels of 28V, 36V, and 48V have been added, and the upper current limit is still 5A.

• With a 48V/5A configuration, a peak power of 240W is achieved.

• Application Scenarios:

• This has gone far beyond mobile phones, aiming to provide full-featured power support for high-performance gaming laptops, professional workstations, and even some lightweight desktops, truly realizing "one line connects the world".

Summary: The evolution path of technological breakthroughs

From 5W to 240W, the evolution of fast charging is an innovation history that solves the three core contradictions of "power, heat, and versatility". In the future, we may see further breakthroughs in wireless fast charging power, as well as deeper optimizations in charging safety and battery health management.

Our fast charging products fully support mainstream protocols such as PD 3.0/PPS, and use GaN and advanced charge pump solutions to provide users with an efficient, safe, and future-proof charging experience.