ST’s NFC expansion board is claimed to provide a complete design blueprint for implementing NFC in applications such as IoT nodes, in which NFC can be used for configuration and network commissioning, and wearable devices, in which it may securely carry data for contactless payments, ticketing or access control.
The expansion board is supplied with a full suite of NFC firmware provided by ST for its ARM Cortex-M based STM32 microcontrollers. The NFC board is complemented by other expansion boards implementing fingerprint recognition, Bluetooth connectivity, M2M communications and a display, to enable rapid prototyping of NFC-enabled end products.
The board is based on the ams AS39230 boostedNFC analogue front end, and ST’s ST54E system-in-package. The board can be connected to various antenna sizes, ranging from 400mm² supporting NFC Reader/Writer functionality down to ultra-tiny SMD antennas for Card Emulation-only functionality.
The active load modulation method of boosting the NFC signal implemented in the AS39230 is claimed to produce an operating volume 10 times larger than the passive load modulation method used in smart cards. At the same time, the AS39230 based system draws 15µA average current in listening mode.
The circuit implemented in the board provides NFC performance in conditions hostile to RF signals, for instance when operating close to or inside metal surfaces, or when transmitting through a very small antenna. The board is said to achieve fast, reliable coupling with any standard NFC reader.
