Mi 11 Pro and Ultra Charging Technology
In addition to performance, Mi 11 Pro and Ultra charging are also worthy of attention, in which both wired and wireless charging reached 67W, and the same speed, reaching zero time difference. This Xiaomi cell phone official science, said the reason for zero time difference, is that Mi 11 Pro and Ultra using a new self-researched 6 times booster second charging architecture, officially brings wireless charging into the era of unprecedented 30V voltage system.
Here is the full text of Xiaomi’s official explanation.
Mi 11 Pro and Ultra is equipped with 67W wireless second charging, which can charge a large 5000mAh battery to 100% in 36 minutes, and the charging speed is zero time difference with 67W wired charging. The reason why the zero time difference can be achieved is that Xiaomi 11 Pro and Ultra adopts a new self-developed 6 times booster second charging architecture, which officially brings wireless charging into the unprecedented 30V voltage system era!
Xiaomi wireless fast charging architecture has gone through 4 generations of technology in 3 years, from the Buck wireless charging architecture (charging power 5W-15W) starting with Xiaomi MIX 2S to the Buck + 2:1 charge pump wireless charging architecture of Xiaomi 9 (charging power 20W), and then to the 4:1 charge pump wireless charging architecture (charging power 30W-50W) adopted by Xiaomi 9 Pro, Xiaomi 10 and Xiaomi 11, Xiaomi wireless charging technology has been leading the industry. And Xiaomi 11 Pro and Ultra’s new self-developed 6:1 charge pump second charging architecture, using 6 times boost + low current method, provides a unique and efficient way for the realization of high-power wireless charging.
The new self-developed 6 times booster second charging architecture, how to achieve more efficient charging?
If it is necessary to fill a pool, the larger the water volume, the shorter the filling time. It is naturally more efficient to feed water through six water pipes at the same time than just one water pipe. The charging process is like storing water. By 6 times the voltage, it can achieve approximately 6 times the speed of ordinary charging, but the heat generation can be similar to that of ordinary charging, allowing users to experience the advantages of supercharged fast charging.
The charging speed is faster, why can the heat generation be close to that of ordinary charging? We can use a simplified mathematical model to explain why the 6 times to boost mode (30V) is more efficient than the previous generation 4 times mode (20V).
If 67W charging is achieved for a 5V battery, the previous generation charging architecture is 20V-3.35A, and the new 6 times boost charging architecture is 30V-2.23A. Calculate the loss of local impedance R:
- 20V path loss I² x R=3.353.35R=11.22R
- 30V path loss I² x R=2.232.23R=4.97R
The local loss of the new 6 times supercharged charging architecture is reduced by 55% compared to the previous generation architecture. This design advantage has a significant effect on reducing charging heat, so it can achieve the same heat generation of the mobile phone and fully improve the wireless charging speed.
Although the principle is simple, it is very difficult to achieve a 6-fold boost charging architecture. For this reason, we have customized two new chips.
Explore the limits of high-pressure and low-resistance technology: Customize the industry’s first 30V wireless charging receiver chip
Xiaomi breaks the limitation of traditional mobile phone charging chips working at 20V and customized the industry’s first 30V wireless charging chip. This customized chip adopts advanced process and design methods to comprehensively improve the switching characteristics and conduction characteristics of the device, so that the characteristic on-resistance (Rsp) is reduced by 28% compared with the previous generation of 20V products, and the area of the device with the same performance is reduced by 20%. Significantly improve the power density of the device. This also enables the miniaturization of Xiaomi wireless charging devices, and finally realizes a unique chip that integrates small size, high voltage, high efficiency, and high power.
Xiaomi’s customized wireless charging chip supports 30V high-voltage output and low-power operation mode, unique high-voltage protection mechanism and power classification protection mechanism to protect the chip safety; customized voltage tracking technology, accurate FOD detection technology, reverse Q value detection technology, and other new technology enhances the safety of wireless charging. With the support of these new technologies, combined with 15-layer security monitoring algorithms, the wireless charging chip can operate stably in up to 8 different charging modes.
Challenge the pinnacle of multi-mode safety design: Customized industry’s first 6:2 charge pump with 30V voltage input
According to the 30V wireless charging technology standard, Xiaomi customized the industry’s first 6:2 charge pump chip. The new topology design can realize 6:2/4:2/2:2 forward or reverse 6 working modes. To achieve the efficiency of 6:2 working mode up to 97%, multi-mode safe and stable switching, the highest efficiency follows mode, 12-fold safety protection, and other core key technologies.
The most challenging difficulty of the 6:2 charge pump chip is the topology design of the conversion architecture and the realization of multi-mode switching. The newly designed conversion architecture has 75% more switches than the traditional 4 times boost architecture, and the entire path requires at least 44 switches. Working together, the design is extremely complicated. To verify the stability of the full-mode collaborative work, Xiaomi has verified the switching characteristics of more than 500,000 times over 6 months, ensuring the safety and stability of multiple mode switching.
Thanks to the 6 times boost charging architecture and two customized chips, a two-stage charge pump, a three-charge parallel design, the latest safe charging algorithm and a new generation of MI-FC fast charging technology, a new MTW silicon oxide negative battery, and the vertical air-cooled 80W wireless charging base, the wireless charging speed of Xiaomi 11 Pro and Ultra are far faster than other wireless charging mobile phones in the supermarket, and it can even achieve zero time difference with 67W wired charging, and it can be fully charged in 36 minutes. Say goodbye to battery anxiety during use, and enjoy the technological experience brought by the many innovative technologies of Xiaomi 11 Pro and Ultra.