I understand that I have exited the NFC WLC function and I currently have X-NUCLEO-NFC07A1. How do I charge the WLC-Listener using the battery charging function shown in the legend?
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I don't know if it's feasible to use NFC to charge the battery. Perhaps a super capacitor can be better used with NFC than a lithium-ion battery. When I think of NFC, I think of a credit card that the user brings to the stationary device for charging credits, and this is done in a short time, a few seconds.
Charging a battery takes many seconds, sometimes several hours.
When I think Wireless Battery Charger, I think Qi Battery Charger.
See: Wireless Battery Charging
Qi is focused on wireless charging above 5 W, while NFC wireless charging currently targets 250- to 1,000-mW charging, with the potential to increase support to at least 3 W. Qi and NFC already complement each other as an in-console solution. Qi chargers typically also implement NFC card protection.
STMicroelectronics and NXP are among the NFC wireless charging pioneers. Products in ST’s ST25 family of NFC and RFID tag and reader ICs feature NFC wireless charging for a variety of NFC-enabled solutions.
“NFC wireless charging provides easy integration into small applications through tiny antenna footprints, with targeted antenna dimensions ranging down to below 0.15 in.2 [1 cm2],” said Peter Neger-Loibner, NFC product marketing manager at STMicroelectronics. “Using PCB or flex-PCB antennas, these products can be an ideal fit for complex form factors. It is this convenience and versatility that make NFC wireless charging so useful for consumers and easy to integrate for developers.”
Panthronics AG also added wireless charging functionality to its product line. Its next-generation system solutions include PTX130W, an NFC wireless charging poller IC, and PTX30W, a fully integrated listener IC.
“Our goal is to simplify NFC wireless charging technology, making things easier for our customers and accelerating its adoption into new applications,” said Alessandro Goitre, director of product management at Panthronics. “This does not mean we compromise on performance; we continue to push the boundaries on what is achievable. The appetite for leveraging the benefit of NFC wireless charging continues to grow. I think we’re seeing the beginning of what will prove to be an amazing era for NFC-based technology in digital styluses, wearables, smart glasses and [smart] rings, hearables and medical sensors. All these devices will improve the customer experience through NFC wireless charging.”
Infineon Technologies is developing a new NFC wireless charging turnkey solution with an emphasis on the power density (received power/PCB size) and the integration of system functions, such as thermal control and battery charging.
“Our goal is to help customers achieve a very cost-effective implementation of NFC functions,” said Qi Zhu, director of product marketing and business development at Infineon. “Reducing the total ownership cost is one aspect. The PCB size limitation of compact devices is another reason customers are asking for a higher level of integration.”
https://www.eetimes.eu/2023-the-year-of-nfc-wireless-charging/
Another issue is energy waste. It's really annoying to have to spend time looking for the right position to get energy transfer efficiency.
- The efficiency drops dramatically at larger distance (z/D > 1) or at a large size difference of the coil (D2/D < 0.3)
- A high efficiency (>90%) can be achieved at close distance (z/D < 0.1) and for coils of similar size (D2/D = 0.5..1)
