Magnus® S3 Sensor IC

Optimized for Moisture, Pressure, Proximity, and Temperature Sensing

RFMicron’s Magnus® S3 single chip family of ICs enables a new class of fully-functional wireless passive sensors consisting of nothing more than the Magnus® S3 chip and an antenna – the same components needed for a conventional read-only RFID tag.

RFMicron is driving a revolutionary change in the RFID market by providing single-chip sensing capability via affordable sensor tags for multiple stimuli such as moisture, pressure, proximity, and temperature. This innovation enables substantially lower cost, easily deployed, maintenance-free and battery-free, sensing solutions to business problems for improved product and quality control.

The Magnus® S3 UHF RFID Sensor Tag IC is designed for use in EPCglobal™ Gen 2 (v. 2.0.0) and ISO/IEC 18000-6C compliant tags. It offers an unprecedented degree of user control and feedback, correction of interference and detuning conditions and allows for precise management of tag response.

Magnus® S3 ICs feature RFMicron’s patented Chameleon™ technology, Sensor Code, On-Chip RSSI Code and Temperature Code. Chameleon™, the first truly adaptive RFID front end, automatically adjusts the input impedance of the IC to optimally tune the tag to varying frequencies and environmental conditions.

Sensor Code gives the user access to the Chameleon™ self-tuning circuit results as a 9-bit Sensor Code using a standard EPC Gen 2 READ command. The Sensor Code provides a direct measure of the antenna’s impedance. Based on the chosen antenna design and the effect of the environment on the impedance, changes in the Sensor Code indicate a change in the environment.

On-Chip RSSI Code is another capability unique to RFMicron. The On-Chip RSSI Code is a 5-bit digital output that can be read by the reader using standard EPC Gen2 commands and can be used as a data resource providing a direct measurement of the signal strength seen by the tag. This feature is useful in development, characterization and system installation to manage the response of large tag deployments.

Magnus® S3 also includes an accurate temperature-sensing circuit, which generates the Temperature Code. The Temperature Code is a 12-bit number which can be read using a standard EPC Gen2 READ command. By retrieving the Temperature Code and applying a simple formula determined at calibration time, the Temperature Code can be converted into to a precise temperature measurement.

The Magnus® S3 Sensor Tag IC enables cost-effective solutions which today can only be achieved by conventional sensors costing 10 to 100 times more.

S3 sensing image


  • RFMicron’s patented Chameleon™ technology enables self-tuning consistent-performing passive tags
  • 9-bit Sensor Code reports changes in impedance due to environmental effects
  • On-Chip RSSI provides an unprecedented level of information on system performance
  • 12-bit Temperature Sensor accuracy +/- 0.3 C from 0 – +50C; +/- 1.0 C -40 to +85 C
  • Meets EPCglobal™ Gen2 (v. 2.0.0) and ISO/IEC 18000-6C requirements
  • Worldwide operation in the RFID UHF band from 860 to 960 MHz
  • User-accessible read-only and read/write memory
    • 64-bit factory programmed unique Tag ID (read-only; unalterable)
    • 176-bit user memory
    • 128-bit EPC™ code
    • 32-bit Access and Kill passwords

Application Areas:

  • Automotive
  • Construction
  • Health Care
  • Industrial / Agriculture
  • Energy
  • Perishables
  • … and many more


3700 N Capital of Texas Hwy
Suite 570
Austin, TX 78746
Tel: (512) 535-4647


Datasheets & white papers are now available in Chinese.