Fast system integration and high speed data transfer are assisted by the availability of SPI and I²C interfaces and by optimised protocols (tunnelling mode and extended mode), allowing bidirectional communication between the device microcontroller and an external NFC compliant device or ISO14443A reader device. AS3955 is able to operate fully powered by the RF field, without any external supply: or from an external 1.65 to 5.5V supply. This, combined with an advanced energy harvesting feature, greatly increases battery life time or even allows battery-less designs.
The IC is fully compliant as an NFC Forum Type 2/4 Tag, ISO14443A up to Level 4, EMVCo: energy harvesting supports up to 5 mA at 4.5V. The chip provides standalone NFC passive tag, functionality, with high-endurance EEPROM memory that reaches automotive grade quality.