STMicroelectronics — ST25RN300 NCI Reader

Compact near field communication (NFC) equipment has to balance antenna size, communication range, certification work, and power consumption. The ST25RN300B-BWLT NCI reader is designed for payment terminals, access-control readers, transportation systems, and IoT equipment that need reliable NFC operation in small spaces.

An embedded Arm® Cortex-M3 microcontroller performs the NFC control functions, covering reader/writer, card-emulation, and passive peer-to-peer communication modes. High RF output power working up to 2.2W helps to extend the interaction range when the antenna area is constrained by the enclosure. Improved demodulation sensitivity complements the transmitter performance, helping the reader to communicate with different card and tag types.

Dynamic power control automatically adjusts transmitted power when a card is close to the antenna. This helps to keep the RF field within NFC Forum limits while preserving output power when greater distance is needed.

Active load modulation improves card-emulation behavior, allowing smaller, battery-powered NFC equipment to communicate while maintaining compatibility with existing NFC standards. Active wave shaping simplifies register settings used to limit signal overshoot and undershoot. This supports monotonicity requirements in NFC Forum and EMVCo testing, helping to reduce design-in and certification effort.

The NFC controller also supports switched-off and low-battery use cases. Proprietary in-frame synchronization helps card emulation remain stable in battery-low and switched-off modes, which matters in phones, wearables, transit equipment and access credentials. For branded connected equipment, NFC can also support accessory recognition, automatic configuration, traceability and user engagement. The ST25RN300 exchanges data with the application processor through the NCI 2.1, 2.2 compliant, logical interface on top of the I²C connection. This makes the ST25RN300B-BWLT suitable for IoT applications that link physical items with digital services.