HOW DOES IT WORK?

NFC 5 Click is based on the ST25R3918, a multipurpose NFC transceiver from STMicroelectronics that enables NFC reader capabilities, passive peer-to-peer functions, and NFC card emulation. This component is designed to meet the needs of Internet of Things (IoT) applications and various consumer or industrial uses, providing outstanding analog performance. The ST25R3918 chip is adept for many NFC and HF RFID tasks, including applications in consumer electronics, IoT for accessory recognition, parameter adjustments, brand security, access management, customer engagement, and more. It complies with ISO14443 and ISO15693 standards, facilitating various NFC functions such as accessory recognition, brand protection, and consumer interaction, alongside supporting NFC Forum Tag types 1, 2, 4, and 5 in reader mode.

Thanks to its noise-reduction receiver technology, the chip stands out for its excellent read range with minimal power output, even in challenging conditions. It incorporates an advanced analog front end (AFE) and a comprehensive data framing system for NFC-A/B (ISO 14443A/B) readers, offering higher bit rates, and supports NFC-V (ISO 15693) reading up to 53 kbps. Additionally, it facilitates ISO 18092 passive initiation and targeting, along with NFC-A / NFC-F card emulation, enhancing device interaction with Android™ phones and enabling the use of Apple® App Clips through simple NDEF data exchanges.

The ST25R3918 also features a low-power wake-up mode that detects cards by measuring the antenna signal's amplitude or phase, coupled with a low-power RC oscillator and wake-up timer that activates the device at set intervals to search for tags.

NFC 5 Click offers flexibility through its support for both SPI and I2C interfaces, selectable via the COMM SEL jumpers. By default, the I2C interface is active, supporting High-speed mode operation up to 3.4MHz, whereas the SPI mode accommodates clock frequencies up to 10MHz. To notify the host MCU of completed commands or external events, like the peer device field, the ST25R3918 signals an interrupt on the IRQ pin. 

The ST25R3918 has separated power and logic supply pins, and thanks to two onboard jumpers, labeled VCC and VIO, this Click board™ can operate with either 3.3V or 5V power/logic voltage levels. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.

SPECIFICATIONS