Called AS3956, it is intended to act as a contactless bridge between a microcontroller and NFC readers or NFC-equipped phones.
The chip is able to operate fully powered by the RF field, without any external supply, and can supply 5mA to external loads. “This, combined with an advanced energy harvesting feature, greatly increases battery life time or even allows battery-less designs,” said AMS.
In the presence of a 13.56MHz field generated by an NFC reader, the chip powers up and notifies its host microcontroller through a wake-up signal, as well as handling the tag activation sequence.
Several operations are then possible, depending on configuration:
- AS3956 exchanges with the NFC device NDEF data stored in the internal EEPROM
- The microcontroller exchanges with the NFC device NDEF data stored in external memory
- The microcontroller exchanges data with AS3956. This operation can be performed concurrently with communication over the RF link, or also in absence of RF power, in presence of an external supply.
In basic operation, the AS3956 acts as a stand-alone Type 2 tag conforming to the NFC Forum standards and supporting NFC communication with a reader.
“Thanks to a high sensitivity ISO14443A front-end and high integrated resonance capacitor, AS3956 offers standalone NFC passive tag functionality in a small form factor. The AS3956 dynamic tag acts as a contactless bridge between sensors and any NFC reader,” said the firm.
SPI and I²C interfaces are available, and protocols include tunnelling mode and extended mode, allowing bidirectional communication between the device microcontroller and an external NFC compliant device or ISO14443A reader device.
Operation is over -40 to 125°C, and applications are expected in heating, air conditioning, hearing aids, infrastructure – roads, bridges and utilities – and smart insulin pens.
Internal EEPROM memory is rated for a minimum 100,000 program/erase cycles, with 10 year data retention at 125°C.
“The rigorous quality processes and numerous validation tests put in place by AMS will give customers confidence that the AS3956 can cope with operation in harsh or extreme conditions and still maintain unimpaired RF, interface and memory functions,” claimed AMS head of marketing Giancarlo Cutrignelli.
The package is either 1.8 x 1.4 x 0.3mm chip-scale or 3 x 3mm MLPD package.