Evaluation board explores NFC use in wearables, IoT applications

July 31, 2015 // By Graham Prophet
For design of wearables, product identification, and smart-city applications for the Internet of Things (IoT), the CLOUD-ST25TA evaluation board is based on the ST25TA02K chip from STMicroelectronics.

The board has everything needed to start adding an NFC interface to any kind of electronic device, from Bluetooth audio products and wearable devices to NFC posters and business cards. It is based on the ST25TA family that consists of a range of NFC Forum Type 4 tag chips that claim the widest range of integrated EEPROM memory size (512-bit up to 64-kbit) along with the most robust memory performance, with data retention times of up to 200 years, the widest operating temperature range (-40°C / +85°C), and an endurance of 1 million erase-write cycles. These devices are suited to Wi-Fi and/or Bluetooth pairing, smart posters (e.g. storing URLs or triggering apps), Vcards containing contact details and ID photo, product identification, asset tracking, and other consumer, industrial, and IoT applications.

Features of the ST25A family include:

- RF performance enabling effective use with ultra-small antennae, using a 50 pF internal RF tunable capacitance.

- UFDFPN5 (1.7 x 1.4 mm) package, suiting the devices for wearables and other IoT applications where board space is at a premium.

- Optional password protection to guarantee data security in the tag.

- A 20-bit event counter that allows analytics to track the level of interest in the information contained in the tag.

- A general-purpose output asserted every time an event occurs in the RF field. This output can be used as a wake-up signal for Wi-Fi and Bluetooth, and it does not require any external components.

An easy-access development platform with full native NFC support, the ST25TA-CLOUD evaluation board costs $5.

STMicroelectronics; www.st.com/cloud-st25ta-nb1507