Integrated wireless phone charging might not be one of the first things consumers consider when it’s time to buy a new car, but it’s becoming an expectation as a key component of a model’s infotainment system.
The convenience and added safety of having an easily accessible charger always available has resulted in wireless charging becoming ubiquitous for car manufacturers as another way to enhance user experience. And not just for high-end trim packages or luxury brands; every major automotive manufacturer offers this feature across more than a hundred models.
The vast majority of these charging units are based on the Qi wireless charging standard, which is managed by the Wireless Power Consortium (WPC) , the global standard development body for wireless power. Qi is used in most major smartphones, including Apple and Samsung models, and has become the industry standard for in-vehicle charging. There are a few reasons for this, including its recognition in the industry, the WPC’s commitment to innovation and evolving the standard, and a broad range of third-party Qi accessories. The WPC also has a highly regarded certification process that ensures charging experiences meet consumer expectations.
NXP and the Qi-Standard
NXP has a proven track record of providing high-performance MWCT MCUs for Qi products, including being the global leader in integrated in-vehicle wireless power. As a result, we’ve established ourselves as thought leaders in wireless power and have been working with the WPC since the beginning of the standard. This includes participation in various WPC working groups and support to drive the specification through its evolution. We also understand the design challenges that come with developing in-vehicle applications, particularly complex electromagnetic compatibility (EMC) design and integration that comes with managing reliable performance.
Device makers require custom wireless charging designs, which result in schematic reviews and software changes specific to each customer, depending on the specifications of the end design. Our expansive MCU portfolio covers the broad power range of devices that feature wireless charging, from 1W to 15W driven by Qi spec and up to 50W driven by proprietary protocols. Beyond the devices, we also provide certified software and hardware designs and support. NXP's designs in development for 25W are on track with the WPC Qi2.2 standard under development.
Two NXP product families, in particular, are helping to shape Qi performance and adoption, the MWCT2xxxS and MWCT2xD2A wireless charging ICs. On 26 November 2024,
NXP's Magnetic Power Profile (MPP) multi-device wireless charging transmitter using the MWCT2xD2A MCU passed the Qi2.0 MPP compliance testing and IOP testing. This is a key milestone in Qi compliance, as Qi2.0 is the latest WPC standard and the MPP ensures that the wireless charging transmitter and receiver coils are aligned perfectly for efficient power transfer.
NXP’s Qi2.0-certified MPP multidevice wireless charging transmitter
On-Chip Authentication: A New Era for In-Vehicle Charging
OEMs and developers face some very specific challenges when integrating wireless charging, including EMC, power output, and authentication. Today, standard wireless charging requires a dedicated MCU to control the charger and a secure element to ensure the charger is actually Qi-compliant. This is driven by an update in Qi 1.3 that requires hardware-based authentication which protects users from damage that can be done to their devices by using counterfeit products. This is a great feature for users, but for designers, a higher number of distinct parts adds complexity to the design. It also increases the cost of materials (BOM) to have two distinct parts, one of the key pressures facing original design manufacturers (ODMs).
With the introduction of the MWCT2xxxS and MWCT2xD2A families, we’ve built authentication into the chip, eliminating the need for a separate secure element and streamlining the BOM. This approach leverages the NXP EdgeLock 2GO service to connect to the WPC and generate the authentication certificate. The customer or authorized 3rd party can then download their unique certificate onto each MCU for production. Developers will be able to spend less time on external secure element integration into the system, which is time-consuming. The MWCT2xxxS and MWCT2xxxA families also feature two devices for dual charging driven by one MWCT MCU, so instead of needing two chips for this functionality, ODMs can offer this feature with a single chip.
NXP’s wireless power portfolio supports devices designed for in-vehicle, consumer and industrial wireless charging solutions
Ready for the Future of Wireless Charging
The MWCT2xxxS and MWCT2xD2A families also consist of MCUs tailored to the consumer market segment which can be used for wireless charging stands and wireless charging cases. This extends the wireless charging technology with a full spectrum of charging options to support diverse markets including automotive, healthcare and IoT, among several others.
Like any technology standard, Qi will continue to evolve and require new specification releases. This would typically require design changes from device makers to achieve certification or maintain compliance. These MWCT2xxxS and MWCT2xD2A devices provide future-proofing for wireless charging designs with flexible SW and OTA FW updates, so as new Qi standards are introduced, existing chips can stay in service with just a software update. These new families also cover a wide range of memory requirements with options ranging from 128 kB to 4 MB for a wide scope of application on top of Qi charging, for example, CAN and LIN communication with cars, enabled by TJAxxxx transceivers and NFC for card protection, low power wake-up of the charging controller and digital key functionality, enabled by NCx3321.
The introduction of on-chip authentication will make a dramatic difference for OEMs that will no longer be required to add a separate secure element for Qi authentication, reducing the overall cost of the wireless charging module. NXP has more than 30 engineers, with deep expertise and experience across regions, dedicated to delivering innovative MWCT system solutions as the future of wireless charging evolves. Visit our Wireless Power page to further explore our wireless charging portfolio.
