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How to Effectively Use EMC Compliance Testing Standards

Published Date
Author Cadence PCB Solutions

Key Takeaways

  • What are EMC compliance testing standards?

  • Are there certain standards that I must follow?

  • What is the best way to make sure that I am in compliance?

Questions → ideas → action

Taking the right action starts with asking the right questions

I have heard more people than I can count say, “There is no such thing as a stupid question.” Or a more creative version, “The only stupid question is the one that is never asked.” These sound good and are meant to be encouraging to those, like me, who are reluctant to ask for answers that we feel we should already know. As with many fears, they can be irrational and even harmful if they leave you unprepared to take the necessary action at a critical time. In fact, the best actions typically follow good ideas that were born as the result of asking the right question(s).

There are many forms that questions can take. For example, in science and engineering, the most common method of querying is testing. And one of the most important of these examinations is EMC testing, which assesses the degree to which EM radiation from your board impacts other components or circuit operation, both locally and on nearby electronics. EMC testing also examines your board’s susceptibility to external radiation. As excessive EM interference can disrupt PCBA performance, there are regulations that govern its presence. Let’s look at the EMC compliance testing standards and then devise a method to most effectively use them. 

What are the EMC Compliance Standards?

Good question. Probably, the best way to answer this question is from the perspective of why the standards are needed in the first place. Today, electronic devices and products are pervasive practically everywhere, and they are the primary reason for the quality of life that we enjoy. Moreover, the products that we use are increasing in functionality, while shrinking in size. This means that the natural EM emissions from current flow through electronic devices can introduce disruptive EMI and RFI within the electronic device, as well as generate emissions that can affect nearby electronics. Preventing or minimizing the effects of this type of interference is the objective of EMC compliance standards.

Therefore, EMC compliance testing standards can be viewed as a means of protecting circuit boards and electronic devices from EMI, such that the intended operation can be realized. 

Which Standard(s) Apply to My Board?

Great question. The answer to this question is critical as it directs what actions or testing must be done before your product will be allowed to be distributed to end-users. And as you can probably assume, the specific answer depends upon the function of your board, where it will be used and the classification(s) to which it can be assigned.

EMC Compliance Standards Classifications

EMC Product Family Standards

These standards apply to products that have characteristic commonality. For example, products that may be used in the same environment.

EMC Product Standards

Specific products may have standards that are only applicable to them. For example, EV charging systems or alarm end electronic security systems. 

Generic EMC Standards

These standards are for products without a specified  product family standard. These are divided according to the environment, residential or industrial, and emission (outgoing radiation) and immunity (incoming radiation).

An example of the types of testing that may be required for a product is shown in the figure below.

 

An example of the types of EMC compliance standards for a commercial electronic product

Common EMC standards for an electronic product with unintended radiation

EMC compliance testing standards are typically set by the regulatory bodies of individual countries.  In the US, for example, the FCC and the US military are the overriding regulatory bodies; although, many of the standards are developed and published by IEEE/ANSI. In any case, the best place to start in determining applicable standards is with IEC-61000. 

How do I Optimize EMC Compliance Testing? 

This is an excellent question! The best way to optimize EMC compliance testing for your board is to ensure it meets the following testing attributes:

Optimal EMC Compliance Testing Attributes:

✅    The minimal number of tests are performed.

✅    The correct types of tests are performed.

✅    All testing is certified and documented.

✅    Your board passes each test without redesign.

If you can check off all of the boxes above, then you have achieved the best testing regimen possible for your PCBA or electronic product. Achieving the above is not as simple as it may sound, but it is doable if you follow the steps below:

Optimal EMC Compliance Testing Steps: 

    Step #1:    Determine the correct classification(s) for your board.

    Step #2:    Compile a list of the essential tests for your board and the compliance criteria for each.

    Step #3:     Perform EMC simulations during design and make modifications to the board  design to ensure EMC compliance criteria is met.

    Step #4:    Test your board and make sure that all testing is done by an approved facility.

    Step #5:     Obtain documentation that verifies the testing and the results.

Irrespective of the specific tests for your board or product to meet EMC compliance standards requirements, the process can be optimized by ensuring that your board does not exceed constraints during design, which is only determinable with an advanced PCBA design software package, such as Cadence’s  PCB Design and Analysis package Allegro PCB Designer.  Not only can this software package integrate SI/PI analysis, which directly affects EM emissions, but onboard Analog/Mixed-Signal Simulation allows for assessing your board’s immunity for unintended radiation.  

If you’re looking to learn more about how Cadence has the solution for you, talk to us and our team of experts.