Operating at 13.56MHz, Near-Field Communication (NFC) began as a data protocol. Today, the NFC Forum’s Wireless Charging Standard (WLC) allows product developers to have high theoretical data speeds, maintain loose coupling and deliver small amounts of power.
NFC WLC is a technology that’s well-suited to small, wearable devices. This technology can already be found successfully implemented in products like smart glasses, fitness trackers & styluses.
This technology is a great option for products with certain challenges, including:
– High frequency allows for smaller coil sizes
– Employ metallic interior to improve performance
– Maximize inner coil diameters to accommodate sensors
– Operating frequency: 13.56MHz
– Decrease need for advanced user dexterity and placement precision
– Increase speed of data transfer
– Transfer more meaningful data
– Protect integrity of transferred data at elevated power levels
– Received power levels up to 3W
Designing a NFC WLC system is all about transferring power efficiently while maintaining communications fidelity. In other words, creating a balance between low power loss and high data integrity.
NFC WLC systems rely on techniques from both NFC data and wireless power to ensure the most efficient power transfer while maintaining the necessary bandwidth to support high speeds of data transfer.
The top-right graph shows a high-Q system (pink line) that is capable of efficiently transferring power, while the green line shows a low-Q antenna that allows for communication signal integrity. The key is to find the balance for the customer’s system.
The lower right graph shows how a high-Q antenna integrates into a system using novel coupling techniques to ensure bandwidth requirements are met. This allows designers the flexibility to trade off performance characteristics to hit specifications.
Qi and NFC WLC both have strengths and limitations.
The chart to the right explores important design considerations for product developers.
When exploring your options, consider criteria such as form factor, user experience, power received and data capabilities.
A NFC WLC system is similar to a traditional wireless power system, with the addition of NFC control. NFC blocks provide the primary function of transferring data, while the remaining foundational blocks function similarly to a Qi-based system. The main difference: As data speeds are increased, power levels must be considered as it will affect the integrity of the data.
The chart to the right provides an overview on the structure of a NFC WLC system.
If your team is interested in creating an innovative charging solution for your small, low-power device, check out the below resources to get started.
Get started with understanding the global specification by going directly to the consortium that created it.
NXP Semiconductors, an NFC Forum co-founder, supplies a majority of the market with NFC-enabled hardware. Browse their hardware options.
As an NXP Gold Partner, NuCurrent is advancing the standard making higher power levels and data rates possible.
NuCurrent is driving industry-leading performance in NFC WLC systems.
The NFC Forum WLC standard currently specifies wireless power transmitted at 1W and data throughput at 106 Kbps.
NuCurrent has advanced this new technology by:
NFC WLC is evolving as an alternative to Qi charging for small, low-power devices. Our NuIQ Platforms offer application-specific designs using industry-leading technology. If you’re looking to innovate in a new product category, our NuEva Development Platform will get you market faster and with superior performance.
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