Low-power radio chip extends the reach of the IoT

Other applications include building automation, industrial monitoring and control, and systems for managing lighting, traffic, or parking in smart cities. The device operates in unlicensed sub-1GHz frequency bands, which are available globally. Ultra-narrowband operation allows highly efficient use of radio spectrum and reliable data exchange up to long distances using low-power signals.

In addition, the transceiver enables connectivity to the Sigfox global network, which is being rolled out worldwide to provide a reliable cost- and energy-efficient communication solution for billions of sensors and smart things.

"Building on our strengths in MEMS Sensors, Analog and Microcontrollers, in 2009 we saw the coming need to support emerging IoT applications with a low-power ISM radio for medium-long-range wireless connections and we developed and introduced our own SPIRIT1 low-power sub-1GHz radio that is currently in many applications available in the market," said Benedetto Vigna, Executive Vice President, General Manager, Analog and MEMS Group, STMicroelectronics.

"Now, in partnership with Sigfox, we are opening a new era in ISM radios for the IoT to extend battery life from months to more than 10 years while preserving the robustness and reliability of the connection and reducing maintenance costs for remote and difficult-to-reach sensors."

Tony Francesca, Vice President of Global Ecosystem Partners at Sigfox added, "Our global network, which has been optimised for the lowest device energy consumption and cost, provides an entirely new way of connecting the physical world to the Cloud".

"ST's support for Sigfox, integrated in the new S2-LP radio device, will help system designers bring their IoT concepts to life by leveraging the benefits of our fast global infrastructure and ecosystem."

The S2-LP long-range, low-data-rate transceiver is in production now in a 4mm x 4mm QFN24 package, priced $1.15 for orders of 1000 pieces.

Technical Notes

The S2-LP transceiver is a highly integrated device made possible by ST's wide-ranging competencies including low-power RF analog design and integration with digital blocks comprising the radio baseband. It:

• Supports point-to-point, star, as well as mesh networking topologies thus resulting in a very flexible wireless transceiver for connected objects.
• Delivers extremely low power consumption, drawing only 6.7mA in receive mode, and 10mA when transmitting at 10dBm. Sleep and standby modes reduce the current to just 600nA and 350nA, respectively.
• Receiver sensitivity of -130dBm enables operation over distances up to several hundred kilometers, depending on the environment, thus enabling wide-area coverage.
• Is a flexible solution that can be programmed for operation in multiple worldwide sub-1GHz ISM frequency band: support for Sigfox, Wireless M-Bus and 6LowPAN, as well as IEEE 802.15.4g, which is suitable for home energy-management systems.
• Leverages a full-featured Software Development Kit (SDK) compatible with the STM32 microcontroller family that has proven credentials in the energy-conscious IoT space, and with the extensive STM32 development ecosystem including prototype boards and rich software tools and resources.
• Is Sigfox-ready and comes with a pre-certified Development Kit enabling immediate connectivity to the Sigfox network for evaluation and easy prototyping purposes.