NFC tag-side controller enables battery-free smart sensing IoT solutions

21-03-2023 | Infineon | Semiconductors

Infineon Technologies AG has expanded its product portfolio of NFC tag-side controllers. The new IC is a single-chip solution that allows the IoT industry to create low-cost, miniaturised, smart edge computing/sensing devices, maximising the benefits for end-users and manufacturers. Mobile phones can control and power such devices, with potential applications ranging from medical patches and disposable point-of-case testers to data loggers, smart thermostats, and sensor inlays.

The tag-side controller supports a dual power supply function, enabling it to work in a passive mode (battery-free) based on energy harvesting or in a battery-powered mode, operating as a self-contained sensing node via a 3V to 3.3V external power supply. In passive mode, the whole sensing system, comprising the IC and its connected sensors, can draw power through energy harvesting from the NFC field of a mobile phone. Together with its naturally galvanically isolated sensing interface, these features open up innumerable possibilities for creating innovative sensing use cases needing no batteries and minimal maintenance. This is particularly useful for applications where the power supply must be galvanically isolated to fulfil the safety need.

The NFC tag-side controller is based on a low-power ARM Cortex-M0 microcontroller and combines several key components. These comprise an NFC frontend compliant with the ISO14443 type-A standard and a motor control driver that utilises an H-bridge circuit with a current drive capability of up to 250mA. NGC1081 also provides a sensing unit based on a 12-bit SAR ADC with four analog inputs and a 10-bit DAC with one analog output. The sensing unit also includes an I2V converter and an integrated temperature sensor that delivers an accuracy of ±0.3C over the temperature range of 0C to 45C and ±0.4C from -20C to 0C and 45C to 85C.

This highly-integrated single-chip solution allows customers to implement smart sensing devices with miniaturised product design and smaller system BOM costs. Also, the tangible IC architecture and the well-designed hardware/software partitioning enable customers to produce fully flexible software-defined functions. The configurability and versatility of the controller make it an excellent choice for adjusting to the specific needs of different applications and systems.

Also, its seamless connectivity to mobile phones allows a cloud-based business model to be adopted. This is supported by a lean and scalable mailbox concept that makes sure robust access management to sustain data integrity and security. Application-specific commands and messages from an open protocol interface extend the protocol layer.

By Seb Springall