ST Introduces Secure NFC Chip for Matter 1.5 Smart-home Onboarding

STMicroelectronics has unveiled the ST25DA-C, a secure NFC Forum Type 4 tag specifically designed for the Matter 1.5 tap-to-pair onboarding process. This innovative chip is the first of its kind, tailored for the updated standard to simplify the installation of various smart-home devices, including lighting, HVAC modules, access-control systems, and security systems.

The introduction of Matter 1.5 standardizes NFC as an alternative to Bluetooth LE or QR code provisioning. By utilizing the ST25DA-C chip, users can simply tap their smartphone to the device for commissioning. The chip handles the necessary SPAKE2+ and signature operations, enabling the device to execute these cryptographic steps without a battery, drawing energy from the 13.56 MHz NFC field. This feature reduces failure rates during field installations and facilitates commissioning for unpowered or difficult-to-access accessories.

One of the key enhancements in this chip is the integration of Matter OTA support over I²C, enabling manufacturers to deliver firmware updates through the NFC tag interface. Additionally, the chip incorporates built-in storage for keys, certificates, and Matter attributes, with over 3 KB of non-volatile memory allocated for provisioning data.

Going beyond the onboarding process, the ST25DA-C boasts a secure microcontroller with active shielding, environmental sensors, fault-injection protection, AES-CCM/CTR support, ECDH/ECDSA, and an NIST 800-90B TRNG. It is built on Common Criteria–certified hardware and is designed to meet SESIP Level 3 requirements.

From a hardware standpoint, the device supports both contact and contactless operations, features automatic antenna tuning, and offers ESD ratings of 6 kV HBM and 1 kV CDM. It provides an I²C interface (up to 400 kHz) and comes in a compact 3 × 2 mm UFDFPN-8 package with a temperature range of –25°C to +85°C.

ST emphasizes that the chip also supports “built-in equipment identification,” which aims to streamline the commissioning process for multi-device kits. This capability could potentially enable users to bring an entire accessory set onto a Matter network with a single tap. By leveraging NFC for onboarding purposes, devices that do not require a BLE radio can reduce their bill of materials, although this is contingent on end-users having NFC-enabled smartphones.

Currently, samples of the ST25DA-C are available, with mass production slated for 2026. Interested parties can access datasheets, evaluation boards, and comprehensive documentation through ST sales channels to explore the full potential of this cutting-edge NFC chip.