David Johnson, Technical Market Analyst
IoT Circuit Protection
The world is moving toward implementing the Internet of Things (IoT), which will have far-reaching and positive impact on virtually all industries and applications.Connecting disparate devices and making them smarter systems gives users and organizations the power of real-time data access that leads to better decision making and productivity through analytics. For instance, already deployed IoT-based industrial automation applications are being used to intelligently monitor factory floor equipment. Programmed to monitor for failure or error messages, these systems allow operators to proactively manage issues to eliminate unplanned factory downtime, boost production efficiencies and help reduce costs. Key, therefore, to making IoT a reality is the continued innovation of low-cost, high speed communications technologies, smart sensors and data analytic software.
As more and more devices are connected, there is a greater opportunity for system failure from various overcurrent, overtemperature and electrostatic discharge (ESD) threats that can cause serious damage in always-on, smart devices. That is why circuit protection plays a vital role. The energy efficiency, reliability and product lifespan features that most IoT system users will think are mandatory directly influence the circuit protection solution a designer selects.
This article presents the high availability needs of IoT business models. It also illustrates why proven circuit protection must be an essential element in maintaining the high level of system reliability expected of the IoT infrastructure. This increased reliability is necessary to aid in the adoption and expansion of the IoT ecosystem.
Where Circuit Protection Makes a Difference
In making the case that broad adoption of IoT will correlate to the growing need for circuit protection technologies is the increasing network of connected, smart devices that will be under pressure to maintain high availability and reliability to ensure access to valuable data. Those depending on a smart grid or intelligent transportation application, for example, expect it to perform with extreme reliability and without the threat of data tampering.
It is estimated that a large percentage of the billions of connected devices expected to make up the IoT over the next few years will be associated with smart cities’ systems such as traffic signals or street lighting and industrial controls. Smart cities will also need monitoring devices for power generation, smart-grid management, energy and security and even future automated transportation vehicles. These devices are designed to operate autonomously with many functioning in remote locations for long periods, perhaps for their entire working lifespan. In these environments, transients such as lightning, burst or ESD occurrences are a constant threat. Network connectivity can make these devices vulnerable making it a requirement that IoT-optimized systems be designed with advanced surge and circuit protection to ensure sensitive circuits operate reliably.
In addition, components and systems are becoming more integrated and advanced, based on increasingly smaller and denser technologies. This, too, makes them more susceptible to ESD. There are also unique circuit protection requirements for newer components that designers need to be aware of. That is why it is recommended that engineers consider ESD protection solutions early in the design process to address the heightened overcurrent and overtemperature sensitivities in today’s integrated systems. In addition, it is important to review and understand the system-level ESD testing required. For example, new protocols are continually being developed to enhance safety in communications and automotive-based applications.
As the IoT infrastructure expands, so too does the need for robust circuit protection at all levels of the power design. Sensor nodes, gateways, and computing platforms will require protection throughout these designs — from AC power connections, to digital ports, down to the board level. Implementing circuit protection addresses both technical and economic issues that can be adversely affected if electrical transient threats are ignored. Ensuring the continuous flow of data to even the most remote devices in the infrastructure supports the very foundation and purpose of IoT.
IoT Ecosystem Circuit Protection
Circuit protection solutions that match the needs of multiple devices in the IoT ecosystem include rugged SPD (Surge Protective Device) modules for harsh computing environments and customized magnetics and trimmers that support efficient power management. Good solutions include today’s advanced Polymer Positive Temperature Coefficient (PPTC) resettable fuses that offer low resistance under normal conditions allowing current to flow. When fault current increases due to short circuit or overload, the device switches to a very high resistance and essentially acts like a fuse cutting off the fault current. When fault is removed, the device cools down and returns to a low resistance state.
There is also an important need for current protection for data lines in exposed networks that are threatened by lighting, power cross, or power surge events. As IoT systems continue to proliferate, systems integrated with proven circuit protection technologies help ensure the necessary reliability while reducing Bill of Materials (BoM) costs. Data line protection requires low conductive in-circuit protection that can be met with Bourns® TBU® High-Speed Protectors (HSPs).
Basically all IoT infrastructure components require a connection between the sensing nodes and the hardware in a computing platform. Many of these connections are made through digital ports that interface with sensitive electronic systems. These connections are subject to electrical transients caused by power surges, lightning strikes, or “dirty power”. If these components are not protected, transients can reach sensitive electronics where they can cause damage to those circuits, making it necessary to shut down the system until it is repaired.
Lightning strikes are the most commonly-anticipated problem, but an engineer must also take into account other issues like ESD, power overload or surges caused by inductive load switching. Most of these issues have been known to the Telecom industry; in fact, they have numerous standards for these events, some of which include IEC 61000-4-2 (ESD), IEC 61000-4-4 (Electrical Fast Transient), and IEC 61000-4-5 (Surge/Lightning). These standards have been in place for many years and are constantly being reviewed and updated.
Mobile devices in the consumer, medical, industrial and military and aerospace industries are constantly increasing functionality in smaller form factors. The IoT will employ these new tablet products that use thinner lithium polymer battery cell technology that also requires circuit protection that meets space-constrained designs. The most popular and considered effective safety circuit protection in use today for lithium-ion battery packs are miniature thermal cutoff (TCO) devices also known as mini-breakers. TCOs provide accurate and repeatable overcurrent and overtemperature protection.
Another IoT circuit protection requirement is in the support of devices that employ touchscreens and other interfaces such as push buttons, switches or connectors that can create ESD events. ESD suppressors or TVS diodes offer demonstrated protection against ESD failure. When the device supports higher throughput in the gigabit per second range, ESD protection requires smaller device capacitance and faster response times. For example, the latest ESD protection devices from Bourns that are available provide sub-picofarad channel capacitance and nanosecond response times.
The IoT relies heavily on “big data” that is supported by wider bandwidth and higher speeds. The trend in circuit protection devices is lower capacitance, higher surge, and faster response time. Smaller footprints and hybrid configurations are also having an impact on the technology. Designers are urged to seek suppliers that continually advance circuit protection technologies to meet these changing requirements and more stringent specifications.
Strong Foundation for Growth
Automotive, factory automation and smart homes and cities are just a few examples of industries that will realize an increased adoption of IoT-based applications that will require the utmost reliability further enabled by circuit protection solutions. Even with the increased usage of wireless devices, the main infrastructure components of IoT systems will continue to be “hardwired”.
The combination of advancements in low-cost, high-speed communications technologies, smart sensors and data analytics along with the higher device reliability gained from established circuit protection technologies provides the strong foundation for continued IoT adoption. New communication protocols and system architectures are being designed to support the bandwidth and computing performance needed moving forward. Smart sensor endpoints will propel data collection and dissemination through integration and communications. Analyzing IoT-provided data from gateways and network infrastructure equipment gives users the power to use information to improve production capabilities, reduce energy consumption and enhance business processes, just to name a few.
Helping to ensure IoT-enabled systems operate to their fullest, circuit protection must be a high priority early in the design phase. Efficient circuit protection takes away one of the biggest concerns about system reliability in an ever more connected world. Designers have a broad selection of proven and advanced circuit protection solutions they can integrate that will help them achieve real-time information access that is at the very foundation of the Internet of Things.