The NFC Tag operates as a dual port memory. You have the the NFC protocol from one side and the I²C bus interface from the other side. It features a 1 kB EEPROM memory. The chip does not have to be powered when being accessed from the NFC side.
NFC (or Near Field Communication) is a great technology for transferring data on a short distance (a couple of centimeters). This attribute makes this technology appealing for security key provisioning. Many smartphones are today equipped with the NFC technology.
Integrated NFC tag NT3H2111 (NXP)
Communication using I²C bus
1 kB EEPROM memory
Optional interrupt output
Optional energy harvesting output
Operating current: 240 µA
Operating voltage range: 1.7 V to 3.6 V
Operating temperature range: -20 to 70 °C
Mechanical dimensions: 16 x 16 mm