What is an NFC Chip?

NFC Chip

A Near-Field Communication chip (NFC chip or NFC chipset) is a silicon component or Integrated Circuit (IC) that can be used in different ways, depending on the targeted application.

When connected to an appropriate antenna, an NFC chip enables short-range, wireless communication between two devices. This provides an additional layer of security, as only devices within close proximity of each other can communicate via NFC.

For instance, the NFC technology can allow contactless communication between:

A payment card and a payment terminal.
Two electronic devices.
A smartphone and a consumer product.

The NFC chips embedded in each component of the system make the wireless communication possible. For example, an NFC chip can be embedded in a banking card and a payment terminal, or in a passport, where it is used to store biometric data.

How does an NFC chip work?
The NFC reader chip
The NFC tag chip
NFC Controller chip

How does an NFC chip work?

An NFC communication system includes two separate parts: an NFC reader chip and an NFC tag. The NFC reader chip is the active part of the system, because as its name suggests, it “reads” (or processes) the information before triggering a specific response. It provides power and sends NFC commands to the passive part of the system, the NFC tag.

The NFC technology is frequently used in public transport, where users can pay using their NFC-enabled ticket or smartphone. In this example, the NFC reader chip would be embedded in the bus payment terminal, and the NFC passive tag would be in the ticket (or the smartphone) that receives and replies to the NFC commands sent by the terminal.

There are three types of NFC chips: NFC readers, NFC tags, and NFC controller chips.

The NFC reader chip

An NFC reader chip can be considered as the main controller of the communication system, as it initiates the communication, powers up the NFC tag, and sends commands through the magnetic field to the passive tag. An NFC reader can also be called an NFC writer, because of its ability to write data into the NFC tag.

Usually, combined with a microcontroller, the NFC reader chip powers up and exchanges information with one or more NFC tags. Supporting multiple RF protocols and features, an NFC reader chip can be used in three different modes: Read/Write, Peer to Peer (P2P), and Card Emulation.

NFC reader chip can be used in three different modes

NFC readers chips are often embedded in smartphones, payment terminals, ticket machines, car door handles, car center consoles, or as part of a broader payment system, such as an automotive or transport application, or a gaming device.

NFC reader door handle

For example, if an NFC reader is embedded in a door handle, the door can be unlocked when the authorized NFC-enabled smartphone is brought in close proximity of the door handle.

The NFC tag chip

An NFC tag chip is a passive device: embedded in an antenna, it is powered by the magnetic field generated by the NFC reader (for example, a smartphone).

An NFC tag responds to specific NFC instructions. For instance, it can reply to an instruction such as “Read command” by displaying its memory content. It can also embed specific features to enable password protection, authentication, or tamper detection, provided these functionalities are pre-integrated in the tag chip.

NFC tag chips are often implemented in the following applications as NFC Touchpoints for:

Consumer engagement
Authentication
Access control
Asset tracking
Home automation
Metering
Lighting

NFC chips can be directly mounted on a plastic film or a textile to form an NFC tag. They can also be housed in a plastic package for mounting on a Printed Circuit Board (PCB).

There are two types of NFC tags: single-interface and dual-interface NFC chips.

Single-interface NFC chip

A single-interface NFC chip is a passive device embedded in an NFC tag, which only communicates with the other part of the NFC system, the NFC reader. Once it is activated by the NFC reader, the single-interface NFC chip enables the exchange of data between the tag and the reader, when they are brought in close proximity.

NFC is the only wireless technology that can be used to interact with NFC tags. Their small size allows them to be easily integrated in space-constrained objects, such as stickers, labels, key fobs, and more.

In addition to their ability to read and write data, some NFC chips also support specific features, such as tamper detection mechanisms and digital signature, which are suitable for identification and authentication applications.

Smartphone reading distance of a wine bottle that embeds an NFC tag in its cork

For example, when an NFC-enabled smartphone is brought within reading distance of a wine bottle that embeds an NFC tag in its cork, the NFC reader can verify the origin of the tag and detect if the bottle has been opened, thereby ensuring the product's integrity.

Dual-interface NFC chip

A dual-interface tag, also called an NFC Dynamic Tag, is coupled with a microcontroller through a wired interface (I2C for example), thereby offering a second communication interface in addition to the NFC wireless link.

An NFC Dynamic Tag chip enables two-way, wireless communication between two electronic systems, even when no power is supplied to the object carrying the NFC Dynamic Tag.

An NFC Dynamic Tag acts as a bridge between two electronic systems and is able to:

exchange data
harvest energy from the NFC RF field to power up a microcontroller

For example, when an NFC-enabled smartphone is brought within reading distance of an electronic device (such as a Bluetooth™ LE headset), the BLE pairing is automatically performed without any additional user operation. The NFC reader (smartphone) detects the NFC Dynamic tag embedded in the headset and recovers the information that enables the BLE pairing.

BLE Pairing with a headset

NFC Dynamic Tags can also be used to monitor the condition of goods. For example, an RFID- or NFC-enabled smartphone can read the information embedded in the NFC tag of a washing machine, such as the details concerning the condition of the appliance, including fault diagnostics. Since many smartphones nowadays offer NFC connectivity, NFC Dynamic Tags can be used by consumer brands to send customers information about their acquired products via a mobile application, thereby increasing their NFC user experience.

BLE Pairing with washing machine

For specific applications such as lighting or motor control, NFC Dynamic Tags can be designed without being coupled with a microcontroller. In this case, the Pulse-Width Modulation interface embedded in the Dynamic Tag allows users to configure LED drivers in the production phase or during maintenance.

Dynamic tag configuration

NFC Controller chip

Contactless smart card

An NFC controller chip combines both an NFC reader and an NFC tag for an integrated solution. It is often embedded in NFC-enabled devices such as:

Smartphones
Mobile Point of Sales (POS)
E-wallet applications (banking cards, bus tickets, health cards, loyalty card, etc.)
Digital Car Keys
Wireless charging devices

An NFC controller chip ensure secure transactions, thanks to the presence of a secure element or a SIM card, and runs in card emulation mode, which means it acts as a contactless smart card.