NFC technology enters the field of wireless charging, helping low-power IoT devices to be easily charged

2021-01-04

In May 2020, the NFC Forum (Near Field Communication Forum, near field communication forum; the organization is responsible for formulating and maintaining NFC technical standards) issued and approved WLC (Wireless Charging Specification) technology to provide small NFC terminal devices (such as smart Watches and wireless headphones, etc.) are easily charged.


▲NFC Forum member, as of May 21 this year. (Source: NFC Forum; Organized by Tuo Dai Industry Research Institute, 2020/05)

The NFC technology standard was mainly formulated by the NFC Forum. Initially, it was jointly developed by Nokia, Philips (renamed NXP in 2006) and Sony. The NFC Forum was established in 2004. Up to now, the number of members has exceeded 120 manufacturers, and it spans multiple fields including Chips, smart phones, TVs, software, financial organizations, etc.; the front-discovered short-range wireless communication technology is based on the basic development of RFID (Radio Frequency Identification) technology, supports 13.56MHz frequency band, transmission distance is 0.2m, and the highest transmission The rate is 424Kbps.

In addition, NFC technology has 4 modes: P2P (point-to-point), Card Emulation (card emulation), (Reader/Writer) card reader and WLC (that is, the new non-contact operation mode is added this time), which is mainly used in mobile payment , Traffic access control and mobile advertising and other fast connection areas. From this observation, although NFC technology is less than Bluetooth technology in speed and transmission distance, the recognition speed of establishing a P2P connection between two NFC devices is faster and more convenient than Bluetooth, and the small transmission distance can effectively reduce interference; in addition, NFC technology has a single It is only connected to one NFC device at a time, so it has high security and is suitable for transmitting financial information and personal information. It is also compatible with RFID technology.

With the approval of WLC technology, the application of NFC communication function expands to provide support for a total of 4 power transmission levels of 250, 500, 750 and 1000mW, and the terminal device only needs to have a built-in NFC chip (without adding a wireless charging coil), which can effectively reduce cost and space. In the future, it is expected to use this to support the "reverse wireless charging" function of mobile phones, so as to conveniently supply power to low-power IoT devices by virtue of the wireless charging pad function of mobile phones. It is worth noting that NFC technology can also be applied to the level of epidemic prevention. Its smart NFC tag function has anti-epidemic features such as "low contact, high security (anti-counterfeiting, anti-tampering, temperature monitoring, etc.), telemedicine", and can be used outside medicines. The packaging can be sensed by a smart phone.

NFC wireless charging and current Qi technology are complementary

Compared with the WLC specification that provides the highest charging power of 1W, the current wireless charging specification Qi can already provide 5, 10 and 30W charging power, but the two wireless charging technologies are complementary due to the different applicable fields:

Qi is mainly used in relatively high power consumption devices such as smart phones (such as Apple mophie wireless charging pads).

The low-power WLC design uses a single antenna of the NFC device to communicate and charge simultaneously (small terminal devices such as smart watches, wireless earphones, and smart fitness wristbands).

In addition, from the perspective of supply, considering that NFC technology has been widely used in the field of smart phones, and NFC Forum member manufacturers Samsung and Huawei have previously developed reverse wireless charging technology in high-end models, which will increase the demand for small smart terminal devices. Rapid growth (for example, smart watches have shown a positive growth of over 60 million in sales volume from 2015 to 2019), so the release of the new WLC specification is expected to make reverse wireless charging popular (including low-end models). It is also possible to pay attention to the developments of other related NFC Forum members such as Apple, Google and Sony. (Source: Top Industry Research Institute)