NFC Tag
A small, unpowered electronic device containing an NFC chip and antenna that stores data and transmits it wirelessly when brought near an NFC reader. Tags are passive devices that harvest energy from the reader's RF field.
NFC Tag
An NFC tagNFC tagPassive unpowered device storing data, powered by reader's RF fieldView full → is a small, unpowered electronic device consisting of an NFC chip bonded to an NFC antenna. Tags are passive — they contain no battery and harvest all operating energy from the RF field generated by an NFC reader or NFC-enabled device. This passivity enables tags to function for decades without maintenance, making them ideal for embedding in products, packaging, and infrastructure.
Tag Architecture
Every NFC tag contains three essential subsystems:
- RF front-end: The antenna coil and rectifier circuitry that harvests energy from the reader's electromagnetic field via inductive coupling and generates the regulated voltage needed to power the chip.
- Digital logic: The state machine or microcontroller that processes commands (READ, WRITE, AUTH), manages memory blocks, and enforces access control through lock bits or password protection.
- EEPROMEEPROMNon-volatile memory technology retaining data without powerView full → memory: Non-volatile storage organized into user memory for application data and reserved areas for the UID, capability container, and configuration bytes.
NFC Forum Tag Types
The NFC Forum defines five tag types mapped to underlying ISO standards:
| Type | Standard | Example Chips | Memory Range |
|---|---|---|---|
| Type 1 | ISO 14443A (Topaz) | Topaz 512 | 96-512 bytes |
| Type 2 | ISO 14443 A | NTAG 213, NTAG 216 | 48-888 bytes |
| Type 3 | JIS X 6319-4 | FeliCa Lite-S | 1-9 KB |
| Type 4 | ISO 14443ISO 14443Standard for contactless smart cards at 13.56 MHz (Types A and B)View full → A/B | MIFARE DESFire EV3 | 2-32 KB |
| Type 5 | ISO 15693 | ICODE SLIX2 | 256 bytes-64 KB |
Practical Considerations
Tag selection involves balancing memory capacity, security features, read rangeread rangeMaximum communication distance between reader and tagView full →, and cost. A simple URL redirect needs only 48 bytes of user memory (NTAG 210), while a product authenticationauthenticationIdentity verification of NFC tags/readers via passwords or cryptographyView full → system requires AES encryption and SDM capabilities found in the NTAG 424 DNA. The physical form factorform factorPhysical shape/packaging of NFC tags: stickers, cards, wristbandsView full → — wet inlaywet inlayAdhesive-backed NFC inlay ready for surface applicationView full →, dry inlaydry inlayNon-adhesive NFC inlay for card body laminationView full →, label, card, or keyfob — is determined by the deployment environment.
Related Terms
Related Guides
Häufig gestellte Fragen
The NFC glossary is a comprehensive reference of technical terms, acronyms, and concepts used in Near Field Communication technology. It is designed for developers, product managers, and engineers who work with NFC and need clear definitions of terms like NDEF, APDU, anti-collision, and ISO 14443.
Each glossary term is cross-referenced with related NFC chips, standards, and other terms. For example, the term 'AES-128' links to chips that support AES encryption (NTAG 424 DNA, DESFire EV2/EV3), and the term 'ISO 14443' links to all chips compliant with that standard.
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