Why Surge Protection Is a Strategic Priority for Industrial IoT?

Every industrial operation knows the cost of downtime. But as factories, utilities, and infrastructure shift toward connected, data-driven systems, even short disruptions can halt multiple processes at once. In the Industrial IoT (IIoT), a single transient voltage spike can ripple across hundreds of devices, from sensors to controllers and gateways, halting production lines worth millions in daily output. This disruption would set back production schedules, trigger maintenance call-outs, and risk compliance.

Such incidents often happen in the background, invisible to operators until a failure occurs. Lightning strikes miles away, switching events on nearby high-voltage lines, or even routine cable connections can inject damaging surges into sensitive electronics. These events are unpredictable and can enter a system through power lines, data cables, or exposed interfaces, making it essential to address surge protection at the design stage rather than relying on post-installation fixes.

Protection as a Design Principle

For years, surge protection in industrial systems was often approached as a simple compliance requirement: a small component added near an I/O port to pass regulatory testing. This view worked when devices operated in relatively stable environments or when downtime carried lower operational risk. Today’s Industrial IoT ecosystems operate under different conditions.

Designing for this reality means embedding protection into the architecture from the earliest stages, with performance criteria that reflect field conditions rather than ideal lab scenarios. It requires devices that maintain constant clamping behavior, regardless of the number of transients absorbed or the environment's temperature. By treating surge protection as a foundational design principle, engineers build resilience directly into the system, reducing the likelihood of in-field failures and extending the useful life of assets.

In Industrial IoT equipment, where devices may be installed across large facilities or in locations that are difficult to access, protection choices made during design determine how well the system withstands electrical stress over years of operation. Integrating protection as a core design principle means identifying potential surge paths early, selecting suppression devices that maintain performance under thermal and electrical stress, and placing them where they can respond most effectively.

This approach allows downstream circuits to operate within defined voltage and current limits without oversizing other components, reducing variability in field performance and helping maintain compliance with surge and ESD standards over the system’s lifetime.

The Problem with Conventional Suppression

Traditional protection devices often work well in controlled lab environments but fail in the field. Many kinds of avalanche-type TVS diode exhibit clamping degradation as their junction temperatures rise, resulting in higher clamping voltages being passed downstream during a surge event.

In other words, the very conditions that are most likely to trigger a surge, such as high ambient heat combined with electrical stress, can also reduce the protection’s effectiveness. This unpredictability forces design teams to “over-engineer” other parts in the system such as increasing power stage tolerances or adding additional thermal safeguards. which drives up cost and design complexity.

Predictable Constant Clamping from Cold to Hot Junction Temperatures

Engineers are increasingly adopting temperature-stable suppression devices that maintain the same clamping performance regardless of heat, surge type, or current level.

Semtech’s SurgeSwitch™ family provides an effective solution for constant clamping. Instead of relying on avalanche breakdown, these devices use a MOSFET-based active shunt that engages only during an electrical overstress. This architecture keeps clamping voltages consistent across a wide range of temperatures and surge conditions, helping ensure protection behaves as expected when it matters most.

By keeping performance predictable, such devices make it possible to:

• Maintain protection margins without oversizing downstream components
• Reduce variability in field performance across different climates and installations
• Simplify compliance with IEC surge and ESD standards
• Extend product lifespans and reduce field failure rates

This predictability also has a system-level impact. It reduces the need for secondary protective measures, simplifies thermal and power-stage design, and allows engineers to integrate protection seamlessly into compact layouts. As a result, surge resilience becomes a built-in feature of the overall architecture rather than an isolated safeguard, supporting both reliability targets and long-term maintainability.

Real-World Scenarios Where Stable Clamping Matters

Predictable constant clamping is the most valuable at points in a system where surges are both likely and highly disruptive. These points often coincide with critical interfaces, high-energy power rails, or densely interconnected equipment. Pinpointing them during design allows teams to apply suppression where it will prevent the greatest downtime and performance loss.

In building automation, 24 V control lines often extend across entire facilities, interconnecting HVAC systems, lighting controls, access panels, and distributed sensors. These lines are routinely exposed to electromagnetic interference from motors and relays, seasonal temperature swings, and occasional wiring faults during maintenance or upgrades. A consistent clamp profile allows these systems to withstand transient events without interrupting control logic, degrading signal integrity, or forcing unscheduled service calls.

On the factory floor, I/O-Link masters and smart sensor ports face constant electrical stress from frequent cable connections and disconnections, ESD strikes from handling, and the elevated temperatures inside compact control cabinets. Stable surge protection ensures these high-density networks remain operational, protecting production workflows and reducing the likelihood of repeat failures in the same ports or modules.

And as more industrial systems adopt USB Power Delivery for scalable power distribution (now up to 48 V), the energy behind a transient event can be significant. In these applications, transients from hot-plug events, role swaps, or negotiation errors can deliver high-energy spikes. Predictable suppression keeps these events within safe voltage thresholds, preserving both the functionality and longevity of connected devices.

The Bigger Picture: From Risk Mitigation to Uptime Strategy

For IIoT operators, effective surge protection supports uptime, data integrity, and operational continuity across entire networks of devices. It also enables more compact, efficient designs without sacrificing robustness, which is critical in modern, space- and power-constrained deployments.

The move toward temperature-stable, predictable clamping reflects a broader shift in industrial design toward proactively embedding reliability into the architecture from the outset. By selecting protection technologies that perform consistently in real-world conditions, engineers can create systems that stay online longer, require less maintenance, and deliver better return on investment.

Our latest whitepaper, Protecting the Future of Industrial IoT: Circuit Protection and Power Solutions from Semtech, expands on these principles with in-depth application examples, testing data, and integration strategies that can help engineering teams implement predictable constant clamping as part of a broader reliability architecture. It also explores power integrity considerations and resilient connectivity architectures.

Download the full whitepaper here to see how to engineer reliability into every layer of your industrial IoT deployment.