NFC Sensor Interface Invades The IIoT

The AS3956 from ams debuts as a dynamic NFC sensor tag IC that meets industrial-grade quality standards and provides high reliability in mission-critical applications and in products with a long operating lifetime. The dynamic tag acts as a contactless bridge between sensors and any NFC reader, such as a smartphone, through a host microcontroller. It supports the NDEF messaging protocol in full compliance with NFC Forum recommendations, guaranteeing interoperability with any NFC phones, including Apple iOS devices.


Differing from currently-available consumer-grade dynamic NFC tags, the AS3956 viable for use in:

  • industrial and Internet of Things (IoT) applications exposed to harsh operating conditions, including extreme temperatures ranging from -40°C to +125°C.
  • products requiring an extended operating lifetime, such as HVAC equipment, hearing aids, and wireless sensors for infrastructure such as roads, bridges and utilities. The AS3956’s internal EEPROM memory is rated for a minimum 100,000 program/erase cycles, and offers 10 years’ data retention at +125°C.
  • mission-critical products that require a zero failure rate.

The device includes various features that give the designer flexibility in implementing NFC-based applications. These include the provision of both an I2C and an SPI interface to a host microcontroller, and a wide supply voltage range from 1.65V to 5.5V.


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. In addition, either of two data-transfer modes for host controller communication can be selected:

  1. Extended Mode, a self-timed data transfer mechanism using standard Type 2 tag commands, thus minimizing software overhead on the host controller.
  2. Tunneling Mode to implement ISO14443A Level 4 PICC emulation in line with EMVCo requirements or custom protocols.

Additionally, the AS3956 includes an energy-harvesting capability, drawing energy from the incoming RF field generated by an NFC reader, and supplying up to 5 mA to an external device. The AS3956 comes in a miniature chip-scale package (CSP) measuring 1.8 mm x 1.4 mm 0.3 mm. Unit pricing is $0.53 each/1,000. For more technical information, an AS3956 datasheet is available.


ams USA Inc.

Raleigh, NC