NTAG I2C Plus vs ST25DV04KC

NTAG I2C Plus (ISO 14443-A, up to 2KB) vs ST25DV04KC (ISO 15693, 512B). Compare NFC protocols, memory capacity, I2C speed, and security for dual-interface designs.

Side-by-side specs

Frequency

NTAG I2C Plus: 13.56 MHz
ST25DV04KC: 13.56 MHz

Protocol

NTAG I2C Plus: ISO/IEC 14443-A, NFC Forum Type 2 Tag (Certification ID: 58514)
ST25DV04KC: ISO/IEC 15693, NFC Forum Type 5

Memory

NTAG I2C Plus: 1k bytes (NT3H2111) or 2k bytes (NT3H2211) EEPROM user memory, 64 bytes SRAM buffer
ST25DV04KC: 512 bytes (4 Kbit) EEPROM user memory

Interface

NTAG I2C Plus: RF (contactless NFC), I2C slave (up to 400 kHz)
ST25DV04KC: RF (contactless), I2C (Fast Mode up to 1 MHz)

Temp Range

NTAG I2C Plus: -40°C to +105°C
ST25DV04KC: -40°C to +85°C

Form Factor

NTAG I2C Plus: XQFN8 (SOT902-3, 1.6x1.6x0.5mm), TSSOP8 (SOT505-1), SO8 (SOT96-1)
ST25DV04KC: UFDFPN8, TSSOP8, SO8

Security

NTAG I2C Plus: 32-bit password protection, ECC-based originality signature, configurable memory access control, negative authentication attempt limiting
ST25DV04KC: 64-bit password protection, configurable write protection, lock mechanism

Spec	NTAG I2C Plus	ST25DV04KC
Frequency	13.56 MHz	13.56 MHz
Protocol	ISO/IEC 14443-A, NFC Forum Type 2 Tag (Certification ID: 58514)	ISO/IEC 15693, NFC Forum Type 5
Memory	1k bytes (NT3H2111) or 2k bytes (NT3H2211) EEPROM user memory, 64 bytes SRAM buffer	512 bytes (4 Kbit) EEPROM user memory
Interface	RF (contactless NFC), I2C slave (up to 400 kHz)	RF (contactless), I2C (Fast Mode up to 1 MHz)
Temp Range	-40°C to +105°C	-40°C to +85°C
Form Factor	XQFN8 (SOT902-3, 1.6x1.6x0.5mm), TSSOP8 (SOT505-1), SO8 (SOT96-1)	UFDFPN8, TSSOP8, SO8
Security	32-bit password protection, ECC-based originality signature, configurable memory access control, negative authentication attempt limiting	64-bit password protection, configurable write protection, lock mechanism

Verdict

Choose NTAG I2C Plus (NT3H2111 or NT3H2211) if you need ISO/IEC 14443-A / NFC Forum Type 2 compatibility with larger memory capacity and faster NFC data exchange. The NTAG I2C Plus offers 1024 bytes (NT3H2111) or 2048 bytes (NT3H2211) of EEPROM user memory—2x to 4x more than the ST25DV04KC's 512 bytes—making it suitable for applications requiring substantial data storage such as detailed product information, extended sensor logs, or firmware parameters. Its 64-byte SRAM buffer enables efficient pass-through communication between the NFC and I2C interfaces. The chip implements 32-bit password protection and ECC-based originality signatures for anti-counterfeiting, plus configurable memory access control. However, the I2C interface is limited to 400 kHz (Fast Mode), and the ISO 14443-A protocol typically has shorter read range compared to ISO 15693. This chip excels in mobile-centric applications where smartphones are the primary reader (most NFC-enabled phones prioritize Type 2 tags) and where memory density is critical. Choose ST25DV04KC if you require ISO/IEC 15693 / NFC Forum Type 5 compliance with extended read range and faster I2C bus operation. The ST25DV04KC supports I2C Fast Mode Plus at up to 1 MHz—2.5x faster than NTAG I2C Plus's 400 kHz—enabling quicker microcontroller access for time-sensitive applications. The ISO 15693 protocol provides longer interrogation distances (up to 1.5 meters with appropriate reader antenna design versus typically sub-10cm for ISO 14443-A), making it ideal for inventory management, access control, or industrial tracking where proximity reading is advantageous. While its 512 bytes of EEPROM user memory is smaller, it's adequate for UID storage, configuration data, or compact datasets. Security features include 64-bit password protection (twice the key length of NTAG's 32-bit) and granular write-protection mechanisms. This chip is the better choice for infrastructure applications using dedicated RFID readers, scenarios requiring longer read distances, or systems where the microcontroller needs rapid I2C throughput to service multiple tags.

FAQ

What is the key protocol difference between NTAG I2C Plus and ST25DV04KC?

NTAG I2C Plus uses ISO/IEC 14443-A (NFC Forum Type 2), optimized for close-proximity smartphone interaction with typical read ranges under 10 cm. ST25DV04KC uses ISO/IEC 15693 (NFC Forum Type 5), which supports longer read ranges up to 1.5 meters with suitable antennas, making it better for industrial RFID infrastructure.

How does memory capacity differ between these two NFC chips?

NTAG I2C Plus offers 1024 bytes (NT3H2111) or 2048 bytes (NT3H2211) of EEPROM user memory plus a 64-byte SRAM buffer. ST25DV04KC provides 512 bytes of EEPROM user memory. For data-intensive applications requiring storage of extensive product information or logs, NTAG I2C Plus delivers 2-4x more capacity.

Which chip has faster I2C interface performance?

ST25DV04KC supports I2C Fast Mode Plus up to 1 MHz, while NTAG I2C Plus supports standard I2C Fast Mode up to 400 kHz. The ST25DV04KC's 2.5x faster I2C bus speed enables quicker microcontroller read/write operations, beneficial for applications requiring rapid tag updates or polling multiple devices.

Sourcing NTAG I2C Plus or ST25DV04KC in volume?

Roxtron builds custom RFID and NFC products around both NTAG I2C Plus and ST25DV04KC. Tell us your project — quantities, form factor, timeline — and we'll come back within 24 hours with pricing and lead times.