Every engineer hits the same moment: somewhere between schematic review and design sign-off, the question surfaces, “What exactly do I need to test for EMC?” Get the answer right, and you move toward market launch with confidence. Get it wrong, and you risk costly re-spins, delayed approvals, or a product that can't pass EMC as is. The good news is there’s a clear, structured path through it; and it starts with knowing your product type, its intended use, and the electromagnetic environment it will operate in. In this post, we walk through that logic so you can approach your next EMC test program with clarity and purpose.
Across our engineering work, we typically encounter three distinct product types, each with its own considerations, challenges, and opportunities.
You cannot always know all the product types your customers will use it in; and that's OK. Focus on IC-level standards, which offer valuable and recognized performance information. Having specific IC performance knowledge can be a significant advantage when system-level questions arise later. Additional IC-level test boards are often required, but the investment is well worth it.
These PCBs typically don't conform to IC-level standards or resemble a final system. They are designed for access and flexibility, not regulatory compliance. Before testing, ask: Will the designer, customer, or interested parties value these results? Gaining alignment upfront helps prevent results from being dismissed if outcomes are unexpected. Particularly useful for conducted emissions, conducted immunity, and transient immunity tests.
This is perhaps the most critical category. It is likely what your company intends to bring to the market. All regulatory requirements must be met for market launch or proof of concept for key customers. Testing is driven by the specific product type and its intended environment. The same product may require different tests depending on its use case and target market.
Knowing which EMC standard applies to your product is the essential starting point (for example):
Despite their unique requirements, there is a common testing framework covering transient immunity, conducted immunity and emissions, and radiated immunity and emissions. Transient tests address high-voltage disturbances such as electrostatic discharge (ESD), electrical fast transients (EFTs), and surge events reaching into the thousands of volts, along with automotive-specific transients in the hundreds of volts range. Conducted tests measure the noise a product generates or tolerates through its cables and ports, while radiated tests evaluate the electromagnetic energy it emits and its vulnerability to external fields during operation. Together, these tests give us a comprehensive picture of how a product will perform in the real world.
Figure 1: The aspects of EMC test types.
Meeting regulatory requirements is what drives general and specific EMC test requirements.
To understand what specifically to test, the equipment type and intended use needs to be clarified. Is your equipment going to be mounted in a car, hooked up to a hospital patient, or installed in a nuclear power station?
Next, where in the world will it end up (geographically speaking)? This shouldn’t matter as electromagnetic waves don’t care, but regions dictate clearly defined requirements. Each industry and geographical region may have specific regulatory EMC requirements and regulatory bodies such as:
When you know your application’s purpose (type and use) and the electromagnetic environment it’s going into, the specific tests, levels, and limits become clear. For example: IEC 61131-2 Industrial-process measurement and control – Programmable controllers – Part 2: Equipment requirements and tests specifies all the EMC requirements for that type of equipment in that particular use. It lists the tests and their associated test standards, along with describing the expected performance criteria (product response), during immunity testing.
Finally, we get to the actual EMC testing standards, the how-to-test part. These are a set of guidelines and protocols the labs use to ensure repeatable measurement and reporting of EMC performance.
Once the item meets the levels and limits specific to that product, in that environment, in that particular region, then you are sorted.
Figure 2: Basic EMC Test Selection Flow Example
Tip: Consider designing your evaluation boards to conform to the IC evaluations layout requirements. This can knock out two birds with one stone.
The path through EMC testing is more consistent than it first appears: know your product type and intended use, understand the regulatory environment it must satisfy, and the right standards, test levels, and limits follow naturally. The earlier you establish that clarity in your development cycle, the less disruptive the process becomes. A concept-stage conversation with your test lab can shape layout and component decisions before they’re locked in.
Read all the blogs in the EMCguy series
