NFC Technology In Smartphones & Mobile Devices

The NFC Technology was first introduced into smartphones in September 2011 and is now widely integrated into most phones, whether they are iOS or Android based.

An NFC-enabled smartphone uses an NFC controller chip connected to an NFC antenna.

The controller chip can be defined as a specialized Central Processor Unit which accepts instructions provided by the application processor software and then processes those instructions to complete the NFC tag detection and/or reading NFC tag content.

NFC enabled smartphone diagram
NFC-enabled smartphone diagram

The NFC smartphone antenna can be positioned either on the top, middle, or bottom of the back side of the phone, and it is rarely indicated on the phone case.

Recent smartphones tend to embed their NFC antenna at the top of the device.

NFC antenna position
NFC antenna can be on top, middle, or bottom of the NFC device

Touchpoint connection and smartphone interaction

During an interaction, the tag’s antenna picks up both the necessary energy to operate and an external signal provided by the smartphone and activates the tag (NFC touchpoint) by means of electromagnetic induction between the two antennas.

Thanks to a tiny embedded processing unit and some memory, the tag analyzes the query, processes it, and replies to the messages received from the smartphone.

NFC communication
Communication between smartphone and tag

The communication range between the smartphone and a tag is in the order of a few centimeters.

Among the five NFC Forum tag types, Type 5 tags (variant of the ISO/IEC 15693 vicinity standard) provide the best range of them all, as they have been defined to operate at the best possible distance.

For the best NFC user experience, the use of Type 5 tags is strongly recommended.

For brand recognition applications, ST recommends using the ST25TV, as an NFC Forum certified Type 5 chip.

Smartphone NFC range

So, what can you expect in terms of range? There are many smartphone models with the built-in NFC function, including premium smartphones and most of the mid-range models on both Android and iOS platforms.

Different smartphones have different NFC reading areas and ranges. This is due to the following factors:

  • Antenna positioning
  • Antenna size and quality
  • Effect of nearby components
  • Different power levels

The best position for a smartphone to read an NFC tag is different from one model to the next. Different smartphones with the same applications may exhibit distinct behavior and performance levels.

NFC smartphone scanning delay

Even when NFC is enabled, a phone is not continuously checking for nearby NFC tags. Instead, it checks periodically if there are any NFC tags nearby waiting to be read.

This is not related to the tag technology but inherent to each and every single phone; there are no rules, the checking interval depends on several different factors including manufacturer preferences, operating system, power settings, other background applications taking up processor time, and many more.

NFC range smartphones
Read range differences from various smartphones

The NFC implementation is smartphone-dependent and can be very different from one device to the other. This has a direct impact on the user experience.

What kind of information can be exchanged?

NFC tags can contain two different types of data:

NDEF format (NFC Data Exchange Format)

The first type of data is called NDEF (NFC Data Exchange Format) information, as normalized by the NFC Forum. NDEF formatted content is fully managed by NFC smartphones and can trigger a dedicated response from smartphones such as launching a browser to open a specific web page (URL), calling or texting a given telephone number, or adding a new contact to the phone’s directory.

Proprietary with dedicated content formatting

The second type is proprietary with dedicated content formatting, which in this case would require a dedicated mobile app to interact with the tag.

For example, if the tag embeds a NDEF-coded URL, the smartphone will automatically open a web browser to the target webpage. In case of a tag with proprietary commands, an NFC mobile application is needed to take best advantage of all tag features.

 

Whitepaper NFC design

 

Discover our NFC / RFID Product Portfolio

ST25T NFC tags

nfc rfid tag

The ST25T series of NFC tags feature:

  • 13.56 MHz HF interface
  • ISO 14443 A/B, ISO 15693 and NFC Forum compliance
  • From 512-bit to 64-Kbit memory
  • Up to 32-bit counter with anti-tearing
  • Field detect output
  • OTP bytes
  • Software and eval tools
  • Antenna design tool

ST25D Dynamic NFC tags

nfc rfid dynamic tag

The ST25D series of dynamic NFC / RFID tags feature:

  • 13.56 MHz HF interface
  • ISO 14443A, ISO 15693, NFC Forum compliance
  • I2C interface
  • 2-Kbit to 64-Kbit memory
  • Energy Harvesting
  • Configurable output signal (GPO)
  • Fast Transfer Mode
  • PWM outputs
  • Software and eval tools
  • Antenna design tool

ST25R NFC / RFID readers

nfc rfid reader

The ST25R series of HF & UHF readers feature:

  • 13.56 MHz HF
  • 840-960 MHz UHF
  • ISO 14443 A/B, ISO 15693, ISO 18092, ISO 18000, ISO 29143 FeliCa, NFC Forum, EMVCo & PBOC
  • Very High Bit Rate
  • Peer-to-peer
  • High Output power (up to 1.4W)
  • High Receiver sensitivity
  • Automatic Antenna tuning
  • Software and eval tools
  • Antenna design tool

ST25 NFC - Complete Training (17 videos)

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