With more and more functions of smartphone integration, it is not just to go up to WeChat, brush Taobao's stuff, smartphones play a "brain" role in the Internet, smart home, smart cars, A lot of new fields such as drones require smartphones to control, but the problem is coming: What should I do if my phone is out of charge? And because of chemical systems and structural restrictions, the energy density of lithium polymer battery is difficult to achieve rapid breakthrough. Therefore, the rapid charging technology has become a "curve to save the country" program.
But the problem is coming, we often see a mobile phone equipped with Qualcomm Snapdragon XXX processors in evaluation or manufacturers, support fast charging technology. In Qualcomm official website, the author also found that the fast-charged word is written in the processor parameter table, which is easy to make consumers to make a mistake, and the mobile phone with the sloth XXX processors support fast charging, in fact, this is incorrect Why? Let's discuss it together.
What kind of "processor" supports fast charge
For example, the official website said, Qualcomm, now QC2.0 fast charge technology has been put on the Snapdragon 400 series, and we simply understand the full line of support is fast, and QC3.0 is also suitable for adaptation, such as flagship. Dragon 820, mid-end Snapdragon 652, I believe that the Snapdragon 400 series will also support QC3.0.
In the United Kingdom, the author did not find the "processor" that supported the fast charge on its official website, but the mobile phone on the market supported the PEP fast charge. Similarly, Samsung's Exynos processor does not clearly point out support fast charge, just product (referring to terminals).
Today's common fast charge standard
Today's fast charge standards are: Qualcomm: QC2.0, QC3.0; Liaotai: PEP; OPPO: VOOC and standard USB-PD protocol. The high-pass / associated fast charge agreement is to speed up the charging speed, and the OPPO's VOOC will support the power output by increasing the current, and the PD protocol will support up to 100W power output. It is also believed to improve the voltage. Today's mobile phones, such as NEXUS 6P, is achieved by low voltage high current (5V / 3A).
The fast charge principle of other brands on the market is basically the same, it has joined their own private agreement, so much discussion.
2 misunderstandings about fast charge
Many people may not be optimistic about the fast charge, the online view is mainly concentrated in two points, 1. The fast charge is not good, 2. The battery is easy to be bad. The author first lists several measured examples to explain the problem.
Popular thousand yuan mobile phone charging speed test
The above is the data for the 2015 millennium charging speed test, where the list of red LeTV 1s is the only mobile phone that supports the fast charge in the 9 test machines, and the test results also show the amount of 10 min. Reaching 690mAh, more than 2 times more powerless than usual without fast charge. (This is not to advertise, just borrow data description facts)
And when the fast charge is easy to make the battery early, this is indeed a little truth. In the case of UNACK and Qualcomm, the 9V / 12V voltage entered the phone through MicroSB, and the translation process will cause a lot of power to the battery protection board inside the phone. Fever will inevitably reduce the service life of the original. But in fact, we don't have to worry too much as a user. After all, it is necessary to support the fast-charged mobile phone in design. For example, the wiring of the PCB board will be wider. The components used are better, the battery will also use the current. Products to withstand capacity of 1C or even 1.5C standards ensure safety in high-increasing environment.
5 conditions support fast charge
Specifying the n conditions to realize the fast charge. First, take a quick charge throughout the process, take Qualcomm QC as an example, when the phone is inserted into the charger, the phone loads a voltage in the D + pin, because the charging head is default Let D + / D-short circuit, so the mobile phone detects the D + / D-voltage consistent, after this voltage maintained 1.25s, the charging head that supports QC2.0 will disconnect D + / D-, at this time, D + has voltage D- no, The mobile phone and charging head successfully "Handshake", the phone reads the data of Voltage_max in Power_supply, and applies for different output values to the charging head by loading the charging head to the charging header.
Qualcomm QC handshake example
And the Liaotai and the PD protocol are issued by the PMIC, and the "handshake" is transmitted through the USB VBUS to the charger. The charger will change the output voltage, Liaotai and the PD protocol in accordance with this dynamic pulse signal instruction. D- use (although we are difficult to buy only data cable with Vbus and GND), the cost is lower than Qualcomm, but the control logic does not have high pass QC to be simple, and because of its pulse signal transmission, anti-electromagnetic interference And stability is still to be verified.
PD protocol handshake example
After the phone applies for output voltage / current to the charger, transfer to the mobile phone terminal through the data cable, the phone is repeatedly buck (VOOC has integrated the buck circuit in the charging head), load the dynamic voltage to the battery protection board. At both ends.
From the above process, we can find that there are 5 conditions to achieve fast, which is 1. Charging head, 2. Wire, 3. Wire web interface, 4. Internal buck circuit (including fast charge chip + circuit and software on hardware Agreement on the protocol), 5. In this case, the author is not analyzed, please see the reason: "The whole people's flash expressions are coming to your mobile phone," there is no OUT "
In these conditions, we don't seem to see the three words about the processor, so the fast charge and processor do not necessarily contact. Usually, the Snapdragon XXX supports fast charge. In fact, the chipset bundled with the Snapdragon XXX supports fast charge, just like the Snapdragon 810 has a RF360 radio frequency module, is also a bundled chipset, and the processor itself There is no necessity link (although RF360 is an AP, the baseband module in the processor is to be corresponding to the baseband module in the processor, but the author is not discovered to accommodate the "space" of the power management module in the Snapdragon 810 chip. Of course, many manufacturers will reduce these bundled chips, allowing the "propaganda" to support fast charge "processor" without fast charge function, which may be due to the factors of cost control or 2. Very fast Rejoice, such as OPPO's VOOC.
Of course, in order to obtain more powerful fast charge technology, many pursuit manufacturers will not use high-pass chipset / circuit, which is replaced by a stronger third-party fast charge management chip, for example Texas Instruments, Fairchild, Han, specific models are not enumerated, they have more power carrying capacity in compatible with Qualcomm QC / Lianfa PEP. Simply, we can understand the official bundled fast charge chip, such as Qualcomm PM8994 + SMB1357 as "public version", and use third parties such as Ti, Fairchild, to understand the "super public" design, and castrated fast charge The chip does not support the understanding of the fast charge (for example, only 5V output) is "shrink" version.
Summarize
Fast charge involves multiple aspects, and supporting fast charge is also independent of the processor, more reason is support for the support, battery, charger, etc. of the processor peripheral chipset. With the popularity of Type-C, the PD protocol has been perfect, I believe that it will usher in a big event in the future. However, after all, its own agreement can earn a big earning in the surrounding accessories market, and the development cost of their own fast charge needs to be shared through the market. It seems that this big one is far away.
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