Technical Article—Pre-certified interconnects simplify IoT adoption

Virtually endless markets and applications can enjoy improved productivity, control, and efficiency through the Internet of Things (IoT). Many products and systems that offer connected technology have not been used before and could benefit from the IoT.

Sensing, processing, actuation and connectivity are the building blocks of IoT design. Modular, plug-and-play solutions can speed up and simplify new designs for applications. This is especially important if the modular solution includes customized development tools and is pre-certified for international regulatory standards and protocol requirements. There are many different protocols for IoT connectivity. SigFox™ is one of the most useful protocols with built-in infrastructure and remote connectivity.

IoT Application Challenges

IoT connectivity is bringing positive changes to both consumers and business users. For example, in the home, remote doorbells allow users to "call home" from anywhere on the planet, as long as they have access to the internet. In business, factory processes can be monitored remotely, providing data that improves operational efficiency. With sophisticated data analysis, real-time monitoring, and predictive maintenance, the benefits of IoT are becoming a reality. However, many of the attributes that make IoT devices so useful and portable also create challenges that designers must overcome.

An IoT node needs to contain a lot of functions. Typically, this includes a microcontroller (MCU) to manage the system and process data, various types of sensors, and cryptographic technology to ensure that sensitive data is securely stored and transmitted. In addition, a power source is required, usually a battery, to support the increasing number of devices that do not rely on mains power.

Size constraints, along with the limited energy available from batteries, mean that designers have many issues to overcome in selecting and implementing small, ultra-low-power devices and developing sophisticated power management algorithms to ensure that precious energy is not wasted.

Challenges of connecting IoT devices

Another challenge for IoT devices is providing the communication interface to connect the node to the IoT. Designers must choose the most appropriate protocol from the large range available. Some protocols are proprietary and suitable for very specific applications, while others, such as Bluetooth and Wi-Fi are widely implemented but only suitable for short-range applications.

Sigfox is a cellular system that provides low-power, long-range, low-data-rate and low-cost communications for remotely connected devices, especially IoT nodes. For simple M2M communications, the Sigfox network supports simple connections over long distances, far greater than the distance that low-power transmitters alone can reach. The network uses ultra-narrowband (UNB) technology to support low transmit power while maintaining reliable connections.

Sigfox is suitable for almost any IoT application, with no restrictions, as long as the application sends no more than 140 12-byte messages per day and can accept a wireless throughput of 100 bits per second, it provides a reliable, low-power, low-cost solution. But unlike ubiquitous communication protocols such as Bluetooth, knowledge about Sigfox is considered relatively "niche".

Modular Sigfox solution eliminates technical design barriers

ON Semiconductor recently launched a programmable Sigfox radio frequency (RF) transceiver system-in-package (SiP) that integrates an advanced RF system-on-chip (SoC) and all necessary external components (including a TCXO), making it possible to simplify and shorten the design and certification process.

The AX-SIP-SFEU SiP provides simple, device-to-cloud Sigfox connectivity, including uplink and downlink for long-range IoT applications using Sigfox LPWAN communications. The SiP integrates a Sigfox radio IC, discrete RF matching components, all required passive components and firmware in a single package. As the solution is CE pre-certified and verified by Sigfox, it ensures that designers are provided with a high-quality, integrated complete solution.

The tiny 7 mm x 9 mm x 1 mm uniformly coated overfilm package ensures the AX-SIP-SFEU can be deployed in space-constrained, long-range IoT applications such as wearables, asset tracking tags, or any application that requires a small Sigfox solution.

Issues related to power consumption can also be significantly reduced by using the AX-SIP-SFEU, as its design incorporates standby, sleep, and deep sleep modes to save power. In these modes, only 0.55 milliamps (mA), 1.2 microamps (mA), and 180 nanoamps (nA) of current are required, respectively, allowing the device to be powered by a coin cell battery (CR2032). Alternatively, energy harvesting techniques can be used to eliminate the need for batteries entirely.

One of the most daunting aspects of any radio design is getting approvals. The AX-SIP-SFEU SiP is Sigfox certified for use in the RC1 region network, which means it complies with standard RF and protocol specifications, ensuring interoperability. It is also CE certified for use in the European Economic Area.