Wireless charging for consumer applications
Fueling the future
Imagine your smartphone’s battery is dead. Until now, you first must find the charging cable, then connect it to your phone and finally plug it into an outlet. The process works, but it can be a nuisance. Especially if your cable is playing hide and seek or if the jack doesn’t fit the cable. Wireless charging removes the hassle of re-fueling your devices. By using electromagnetic fields to transfer power from a transmitter to a receiver application, it charges your battery without a physical connection. All thanks to a wireless charging power supply.
Now compatible devices from a wide range of receiver applications can fuel up cable-free. These include:
- Smartphones and wearables
- Notebooks and tablets
- Power tools and service robots, such as vacuum cleaners
- Multicopters and electric toys
- Medical devices
- In-car charging
There are many reasons why you should choose wireless charging for your consumer transmitter and adaptor designs. In addition to the obvious ones, like no need to plug in a device and no plug compatibility issues, it’s also safer since there is no contact with exposed electrical connectors. Further, it’s reliable in harsher environments, such as drilling and mining. It also allows for seamless on-the-go charging whether in the car or in public places. Finally, it eliminates tangled charging cables while allowing you to charge multiple devices in parallel.
Wireless charging standards
Currently two wireless charging standards stand out on the market: inductive and resonant. Here’s a detailed look at each and an overview of cutting-edge solutions from Infineon, which as a member of the Wireless Power Consortium (WPC) and the AirFuel alliance is actively shaping the wireless charging trends of tomorrow.
Inductive wireless charging
Qi (WPC) and inductive AirFuel, both of which support single-coil and multi-coil inductive topologies and use frequencies of 100-300 kHz, dominate the market today as measured by volume. Their widespread use can be attributed to their cost-efficiency. Inductive topologies always rely on in-band communication.
System diagram: Inductive wireless charging
Resonant wireless charging
AirFuel also offers a resonant technology that operates at 6.78 MHz. Advantages include better user-friendliness because you can freely place the mobile device in the vicinity of the transmitter (typically up to 30 mm of vertical freedom), and it charges multiple devices of different size and power in parallel. AirFuel resonant communicates using Bluetooth low energy.
System diagram: Resonant wireless charging – class D , half bridge
System diagram: Resonant wireless charging – class D, full bridge
System diagram: Resonant wireless charging – class E, full bridge
System diagram: Resonant wireless charging – class E, half bridge
Mastering today’s wireless charging designs
Today, engineers look for semiconductor solutions that overcome a wide range of common wireless power transfer challenges. First and foremost, engineers require efficient and easy-to-design transmitter solutions. Smart heat management is also essential: it keeps the surface and transmitter at a comfortable temperature and avoids heating the battery of the device that’s charging. A small footprint is highly valued especially for devices that are small in size like wearables. By fitting your designs with a high power rating you can ensure faster charging speed, which will please consumers
Why Infineon has the right solutions
Having a reliable partner by your side is key to maximizing the performance and consumer appeal of your wireless charging designs. At Infineon, we help you master every design challenges with our broad selection of semiconductors and reference designs. We enable you to achieve performance comparable to GaN by using mature and reliable Si technology. Further, we are currently working on medium voltage GaN solutions and plan to launch them in the next few years. They will be of the same maturity level of Si devices with a significant boost in performance.
Choose Infineon to benefit from:
- High performance products with the best price/performance ratio in the industry thanks to cost-effective packages and leading, reliable and mature silicon technology
- High power density in small designs: Enable the lowest switching and conduction losses in smallest packages for MOSFETs and power stages
- Low parasitic packages for MOSFETs (2x2, 3x3 HB) and power stages (DrBridge)
- Highest efficiency: In hard switching topologies, enjoy low switching losses thanks to low input and output capacitances (~20%)
- A wide range of ready-to-use reference designs that help you create your inverter or adapter/charger solution
Explore our portfolio and use our helpful wireless charging selection tool to find the best-fit solutions for your wireless charging power supply designs.
Download your free-of-charge whitepaper and learn the current state-of-the-art wireless charging technologies. Compare technical approaches and find out the benefits of a totally integrated approach to delivering advanced wireless charging solutions in this comprehensive document.
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