Wireless charging

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. Currently, inductive or resonant solutions can be used for the following applications:

• Smartphones and wearables
• Notebooks and tablets
• Power tools and service robots, such as vacuum cleaners
• Multicopters and electric toys
• Medical devices
• Smart home and IoT devices
• In-car charging

There are many reasons why you should choose wireless charging for your application. 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.

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.

Qi (WPC), which supports single-coil and multi-coil inductive topologies and uses frequencies of 110-205 kHz, dominates the market today as measured by volume. The inductive technology relies on in-band communication and ensures simple, efficient and safe wireless power transfer. Due to the high adoption rate of charging smartphones without wires, inductive wireless charging is enjoying widespread popularity. In the future, wireless power transfer is set to become a must-have feature in a wide range of other applications, including power tools, service robots, notebooks, medical and smart home devices.

The global wireless charging market has taken notice of the rapid increase of poor quality chargers that fail to comply with data protection requirements, intended to prevent major damage to host devices. The only way to fight this phenomenon: establish and implement standards that achieve a uniform level of safety, security and conformity. The WPC Qi Authentication Standard represents the Wireless Power Consortium (WPC)’s efforts to create certified authentication standards for leading players in both consumer and industrial markets.

Ensuring you, your data, and your devices remain secured and safe, Infineon has added a new member to its OPTIGA™ Trust family, the OPTIGA™ Trust UWP. With this integrated turnkey solution, we clearly support the notion of one standard for all.

AirFuel offers a resonant technology that operates at 6.78 MHz. Advantages include better user-friendliness because you can freely place the 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,  whereas proprietary resonant solutions do so via in-band communication. To develop resonant solutions, two main topologies can be used: Class D (full-bridge or half-bridge) and Class E (single-ended or differential) amplifier.

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

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 your design challenges with our broad selection of semiconductors, and latest and upcoming reference designs.

Choose Infineon to benefit from:

• Compatibility with the leading standards – inductive and resonant
• Innovative and unique reference designs for better transmitter, receiver and adapter performance
• Powerful and cost-effective solutions for high performance, smart, and secure wireless charging solutions, supported by Infineon’s unique wireless power controllers
• Solutions for applications beyond smartphones
• Automotive and industrial-qualified components and solutions
• Reduced BOM thanks to leading silicon technology and upcoming new technologies, such as CoolGaN™
• A strong, experienced partner

Discover Infineon’s key products for consumer and automotive solutions.