Comparison of advantages and disadvantages of three mainstream factions of mobile phone fast charging

　Since smart phones enter the era of large screen, the issue of endurance has become one of the more concerned aspects of users. In the current case of no breakthrough in battery production technology, mobile phone manufacturers choose to increase battery capacity, accurate power management scheme and provide fast charging and other means to extend the battery life. No matter from the aspect of mobile phone design or practicality, the fast charging technology is undoubtedly more advantageous than the first two methods. It not only simply and roughly solves the problem of endurance, but also more close to the current faster and faster pace of life, more practical.

At present, there are many advertisements about mobile phone fast charging in the market, such as PD, QC, PEP, FCP, dash and vooc, which look various, but they are basically achieved by the following ways:

The voltage is constant and the current is increased;

The current is constant and the voltage is raised.

Except that dash and vooc belong to high current fast charging technology, the rest are basically high voltage fast charging schemes. Whether it is high voltage or high current, the final way to improve the speed of fast charging is to increase the power. Now, let's take a look at the three mainstream fast charging factions.

Qualcomm quick charge (QC) faction

At present, high pass quick charge technology has developed to quick charge 4.0, but the mainstream is high pass quick charge 3.0, which adopts high voltage and low current quick charge scheme.

QC 1.0: only support charging power up to 5V / 2A;

QC 2.0: provide 5V / 9V / 12V / 20V four speed charging voltage, and the maximum 3A charging current;

Quick charge 3.0: on the basis of QC 2.0, with 200mV increment as one gear, it supports flexible selection of 3.6V to 20V voltage, which is convenient for mobile phone manufacturers to adjust according to product requirements, so as to achieve the best charging efficiency. At present, many Xiaolong processors, including Xiaolong 821, 820, 620, 618, 617 and 430, support qc3.0. QC 3.0 quick charging head is standard on the market, and LG G5 and Xiaomi 5 mobile phones support this protocol.

As for the latest generation of quick charge 4.0, it has been confirmed that it will be supported on the next generation of flagship chip, snapdragon 835 processor.

MTK: pumpexpress plus (PEP) faction

The principle of the MTP pump express plus fast charging technology of MediaTek is basically the same as that of Qualcomm QC fast charging technology, which is to obtain more charging power by increasing the charging voltage at the same time of constant current. The latest pump express 3.0 claims to be able to charge a smartphone with 70% power in 20 minutes, while reducing power consumption by 50% compared to the pumpexpress plus, indirectly reducing heat.

Pumpexpress allows the charger to determine the initial voltage required for charging according to the current, issue pulse current command to the charger through the built-in PMIC power management integrated circuit, adjust the output voltage, and gradually increase to the maximum charging current. Compared with QC 3.0's method of 200mV as one gear increment, the micro adjustment range of pumpexpress 3.0 voltage is only 10mV, and the theoretical maximum can provide 5A charging current.

Oppo vooc flash charge faction

"Charge for five minutes, talk for two hours" is the classic advertising word of oppo mobile phone. It uses the oppo vooc flash charging technology, which adopts the principle of low voltage and high current. Under the condition of keeping the voltage unchanged, increase the current to improve the charging speed. In addition, oppo has now launched the vooc super flash charging technology with faster charging speed.

Oppo flash charging technology can pre charge with low current and constant voltage when the battery power reaches a certain level, and start charging with high current and constant voltage. The energy conversion loss is greatly reduced, which can effectively alleviate the heating phenomenon of the fuselage in the charging process. Oppo original quick charging head supports 5V / 4A power output at most, and 5V / 2A power output can be realized on the inserted mobile phone which does not support vooc flash charging.

In addition, many manufacturers have introduced their own fast charging technology based on QC or PEP, such as fast charger protocol (FCP) on Huawei mobile phone, dash fast charging on mobile phone, moto turbo fast charging, vivo dual engine fast charging based on qc2.0, Meizu mcharge 3.0 fast charging based on PEP, Jinli lightning fast charging based on two charging chips, etc.

The recently released glory magic is still a high current fast charging scheme in essence. However, combined with the battery material transformation and a new charging circuit, it provides a fast charging scheme of 5V / 8a, 40W charging power. The official website has a nominal charging time of 40% in 10 minutes and 70% in 20 minutes.

Of course, many users have misunderstandings about the fast charging technology of mobile phones. They think that the CPU of mobile phones determines what kind of fast charging technology it is. For example, Qualcomm snapdragon SOC is equipped with QC fast charging protocol, MediaTek is equipped with MTK fast charging, and Samsung exynos is equipped with AFC fast charging, which is a mistake. In fact, many fast charging chips and circuits can be purchased independently. Many MediaTek models of vivo support dual engine flash charging technology based on qc2.0 standard, while Samsung Galaxy note 7 also supports QC, PD and AFC standards.

It seems that there is no inevitable causal relationship between the fast charging protocol and CPU, which requires users to select a fast charging charger for their mobile phones. Only by selecting the right charger can they enjoy a safe and fast charging experience.