The development: The fast charger from QC1.0 to QC4.0

Fast charging technology is changing with each passing day. Today, hundreds of players in the charger market contend. Qualcomm QC fast charging still dominates the market. Now QC fast charging has developed to the 4th version, and each version has been made revolutionary progress. The short replacement time from QC1.0 to QC4.0 will inevitably make the masses complain inevitably.
Since 2010, large-screen SmartPhones represented by Android became more quadrupled, and the battery capacity doubled. 2000mAh has become the standard (currently up to 6000mAh). If it is still charged at 5V0.5A, it is too Unsatisfactory as like "two hours of charging, talking 5 minutes ", so the charging power speed must be increased. How much to improve? 

Let's get a 5V1A first. it is too slow, USB-IF indicates: "Try 5V1.5A." which is also not good enough, at this time Qualcomm spoke: "We want to go to 5V2A." Then, QC1.0 came out.

With the progress of the times, large-screen smartphones start to erupt, battery life can not keep up, fast charging has become one of the magic weapon for manufacturers to improve user experience, then, QC2.0 was born.

QC2.0: Compared with the old standard, QC2.0 epoch-making changes the charging voltage, from the conventional 5V that has been maintained for many years to 9V / 12V / 20V, and the same as QC1.0 achieves 18W at 2A current. Power and power transmission, and the wire can be used without special treatment.But, when the voltage is increasing and the power being up, while the efficiency is reduced. Every time the voltage increases, the efficiency will be dropped by about 10%, and most of this energy is converted into heat, so the 20V voltage file is almost unused, and only the three files of 5V, 9V, and 12V are reserved. but the surface of the product is very hot, Qualcomm feels that the steps from 5V to 9V are too big, so it can be adjusted continuously in units of 0.2V until the most suitable voltage can be found. What is the most suitable voltage? Qualcomm has its own unique the voltage intelligent negotiation (INOV) algorithm, which is QC3.0.

QC3.0: On the basis of QC2.0 9V / 12V two-level voltage, the voltage level is further subdivided. The unique INOV algorithm is used to set the voltage with 200mV as a level. The lowest voltage can be lowered to 3.6V and the highest voltage is 20V, and backward compatible with QC2.0. Since the Type-c interface is fully used to replace the original MicroUSB interface, the maximum current is also increased to 3A. The voltage is more lower, the efficiency will be increased by up to 38%, the charging speed is increased by 27%, and the heat will be reduced by 45%.
Even though QC3.0 is better than others before, but it can not be recognized by Google, because the USB PD protocol should be used for Google's system. that's why QC4.0 have to be launched soon by Qualcomm again.

QC4.0: Raise the power to 28W again, and compatible with USB PD support. The 12V voltage file is canceled, the maximum output of 5V can be 5.6A, and the maximum output of 9V can be 3A, and the voltage file continues to be subdivided into 20mV.