Wireless charging solutions and integration trends
Wireless charging has a wide range of applications. From the perspective of power distribution, it can occur from less than 5W (such as wearable devices) to several W (such as mobile phones/tablets, notebook computers, power tools, kitchen appliances) to kW (such as cars). With domestic handsets such as Huawei and Xiaomi as standard wireless charging, the wireless charging brought by mobile phones in 2018 will be very large. Among them, 7.5W and 10W will become the main force.
Figure: Activity site
At the same time, before the Spring Festival this year, there are many 5W programs in the market. These methods are relatively primitive and will only become a gift market this year. However, the demand for wireless charging in this market will also increase. Heating will be a major problem that wireless charging needs to solve.
This is the "Wireless Charging and Fast Charging Technology Forum" jointly held by ASPENCORE's "Electronic Engineering", "EDN" and "International Electronics Business News". Microelectronics' general manager Dai Xingke has "an existing solution for wireless charging." And thinking about the future" questions addressed in the speech. At the same time, he also focused on five points of thinking about the future development of wireless charging. The author also noticed a relatively special product in their home - the protocol (decoy) chip.
Photo: Dai Xingke, general manager of Microsource Semiconductor, made a wonderful speech at the technical forum
The current understanding of the wireless charging market
First he talked about our understanding of wireless charging now, as follows:
Wireless charging technology has existed for many years, and Apple has experienced explosive growth after releasing iPhone X
Wireless charging application products are very wide, such as IoT, mobile phones, laptops, power tools, cars, etc.
Wireless charging applications have a wide range of scenarios, such as home consumption, offices, vehicles, public places, shared areas, etc. The standards for wireless charging applications are not uniform, such as WPC Qi, PMA, A4WP
Demand for wireless charging applications is large, such as the need for more than 3 different application scenarios for each person's mobile phone charging
Currently, there are two types of wireless charging: electromagnetic induction and magnetic resonance. The former is the mainstream. The electromagnetic induction technology used in Apple's mobile phones is a fixed-frequency voltage regulator, which is a small revolution for SoC or system-level people, because the entire circuit and software have to be modified, he said.
According to a market consulting company, wireless charging shipments will reach more than 600 million units in 2018. "But from a practical point of view, 2018 will far exceed this figure - Shenzhen alone has more than 3,000 wireless charging manufacturers, and our company has an increase of 50 customers every day. With so many companies doing, it will certainly promote Breakthrough in the number of transmitters. Personally, I think that wireless charging will be just a need. When you are not using it, you will understand that it is slow and hot and inefficient, but these three shortcomings may be related to personal Use habits. It will be very convenient when you use it," he pointed out.
Wireless charging solutions and integration trends
The following figure shows the principle of wireless charging. It uses magnetic field coupling. “About five years ago, when wireless charging first appeared, I understood that wireless charging is actually equivalent to an electromagnetic oven. There is an MCU in it. It is an opportunity for system manufacturers to have nothing to do with power management. Appeared, wireless charging suddenly disappeared. But now with the introduction of Apple's mobile phone, the market has been re-up. We think this wave of wireless charging will come more fierce." Dai said.
From the circuit principle, the Tx and Rx terminals are very simple. At the Tx end, the MCU controls the driver, then controls the MOSFET and couples it to the coil through a capacitor. Then through the sensor sampling, tell the MCU how much power, and then adjust. This line has its limitations. "Like a few days ago, we used the iPhone X to test on a customer's board and charged it to 9V/1.3A. I didn't know if that was right. But the power of Apple's work is 7.5W. I don't know if it was a wrong control, or There is a problem with my cell phone." Dai always pointed out, "The part of power now, in fact, 5W, 7.5W and 10W that everyone says, is not the core parameter at the end. When I take the cell phone a little or a little further, it's The power variation is very large, so the entire wireless charging design is not just part of the circuit, the structure (including coil size, coil placement, etc.) also determines the final power.
Judging a SoC or MCU company, its solution is mature, mainly because the SoC/MCU's sampling and control are inaccurate because other hardware is the same.
In the wireless charging, the microsource solution mainly provides support for MCU/SoC peripherals, including the driver chip LP1111 and the upper and lower half-bridge MOSFETs.
"We think that wireless charging will eventually be a price war, and it doesn't have much place (function) to play with," Dai said.
Nowadays, there are many components on the wireless charging circuit board, which are prone to processing problems, patch problems, etc. in mass production. Therefore, the industry is also thinking about how to simplify the number of components above. Including the recent rise in resistance, it also caught everyone off guard. "I recently went to a customer. When it was stuck to 2k a month, a resistor and a capacitor were big problems for it. So we made a dual-driver chip LP1120. When a driver and two MOSFETs are completed, Dai always says. In addition there is a driver chip + MOSFET combination chip LP1130, such a SoC plus two LP1130, completed the entire main circuit design. Moreover, the LP1130 is packaged in SO8, which is very convenient for production. In addition micro-source is also doing a more integrated chip, LP1140, which integrates 2 drivers, 2 MOSFETs and voltage and current sampling, using SOP16 package, so that a SoC plus an LP1140 completes the design, can Make production more convenient and reduce costs.
Based on this consideration, the future wireless charging may only require one MCU (overlay protocol part) and one post-installed ASIC, and then add capacitors and coils to complete the final layout. This is more conducive to the popularity of wireless charging, but also can further reduce the size of the circuit board.
In addition, wireless charging applications are a very standard scene in cars. Because the automobile environment is very harsh, it is necessary to ensure that the wireless charging can be safely used in the car. At present, in the part of the car charger, Weiyuan has 1A to 6A products for you to use. These products provide various protection mechanisms required for automobiles. "There are still some thresholds for consumer manufacturers entering the vehicle market. There are too many pits inside. We have spent four years in the home and have demolished the pits inside (including high temperature, high pressure, and impact, etc.)," ​​he added. .
In addition, I also heard a special product, called the protocol (decoy) chip. "We see that we are now doing 7.5W, 10W manufacturers, the domestic MCU obviously lags behind. Their biggest problem is that the compatibility of the protocol is not good, because they want to use the cheapest MCU to drive the market, then the voltage out It was very inaccurate to shake hands with various protocol chips, and under this demand, we made a protocol decoy chip so that the MCU+ chip could deduct 70% of the fast charge on the market. The charger's power tricked it out and fast-charged it. This chip uses ASIC mode, so its handshake is very successful. It can ensure that the falling edge of the rising edge of the MCU signal is very accurate." Dai total explained.
Five Thoughts on the Future of Wireless Charging and Dai's Viewpoints
What are the advantages and disadvantages of 1.SoC built-in driver and discrete solutions?
At present, some chip makers may introduce drivers for built-in SoCs. This will make BOM a little easier and make the supply chain more controllable. From a cost perspective, SoCs and drives are two completely different processes. From the point of view of chip design, the driver requires a high voltage process and is an analog device; SoC is a 5V process and is a digital device. For digital chips, the process is as small as possible (for example, TSMC now reaches 7nm) and the cost is lower. However, our driver is now using 110nm, there is no idea to go down, because for the analog part, the most important is the voltage, current capability and accuracy of the reliability. The MCU is pursuing computing power, cost, and pin count. Therefore, if these two are combined, the cost will rise at least three times or more and the future will be meaningless - it is still meaningful, because the SoC is now priced higher, but it will be below RMB 1 in the near future. From a chip design point of view, the MCU's built-in driver will be advantageous for 5W applications because it does not require high voltage, but for applications above 5W, it will theoretically have no advantage - now there are advantages because the current unit price of the driver is also Too high.
2. What are the advantages and disadvantages of single-chip half-bridge full-bridge and discrete solutions?
There is a domestic company out of a H-bridge single-chip SoC, with their own programs in our promotion. But after we saw the spec, we thought that such a single-chip solution is really a customer need? How is its power compatible? The very deadly thing in it is how big the MOSFET should be. This is a big problem for cost control. All of the demand comes from the entire wireless charging supply chain. Its cost is still "flesh." Until the "bone" is left, SoC's plan will disappear. It's impossible to do a discrete solution. For example, our driver is SO8. The first configuration is very general, and there is no capacity and cost. This scheme has already reached its limit. So, SoC may have advantages at a certain stage, but in the long run, it may show different advantages for different powers.
3. Will wireless charging be greater than the demand for cost?
Obviously, the cost of wireless charging is greater than the volume requirements. The hope for users is that the mobile phone is stable. Of course, small products, such as those used for wearable devices, are used.
4. What are the future prospects for wireless charging between SoCs and simple MCUs?
Many customers now say that they are SoC solutions. So, which kind of SoC and MCU will become the mainstream of the future? I think it still depends on the cost. Because the cost of MCUs is now very cheap, and has matured over the years, SoCs are still far from mature.
5. How to improve the wireless charging efficiency and reduce the heating?
At present, we have measured the efficiency of 85 to 86%, 88% is already the limit. So how to increase the efficiency to 95% is something that everyone in the industry should think about. Is capacitive coupling really the only solution?
ZGAR AZ BOX Vape
ZGAR electronic cigarette uses high-tech R&D, food grade disposable pod device and high-quality raw material. All package designs are Original IP. Our designer team is from Hong Kong. We have very high requirements for product quality, flavors taste and packaging design. The E-liquid is imported, materials are food grade, and assembly plant is medical-grade dust-free workshops.
Our products include disposable e-cigarettes, rechargeable e-cigarettes, rechargreable disposable vape pen, and various of flavors of cigarette cartridges. From 600puffs to 5000puffs, ZGAR bar Disposable offer high-tech R&D, E-cigarette improves battery capacity, We offer various of flavors and support customization. And printing designs can be customized. We have our own professional team and competitive quotations for any OEM or ODM works.
We supply OEM rechargeable disposable vape pen,OEM disposable electronic cigarette,ODM disposable vape pen,ODM disposable electronic cigarette,OEM/ODM vape pen e-cigarette,OEM/ODM atomizer device.
ZGAR AZ BOX Vape,ZGAR AZ BOX disposable electronic cigarette,ZGAR AZ BOX Vape vape pen atomizer , AZ BOX Device E-cig,AZ BOX disposable electronic cigarette
Zgar International (M) SDN BHD , https://www.szvape-pen.com