Basic of EMC Standards

Introduction to EMC standards

When we want to bring an electrical or electronics device into the market, there's a really important rule we need to follow. It's called EMC standards, and these rules apply when we're creating, designing, and making the device. These standards basically set two things: how much radiation the device can emit and the range of frequencies it can use. This might sound a bit technical, but it's like making sure our device doesn't cause problems for other devices that communicate using invisible signals.

The EMC standards define the frequency range and limit of unnecessary radiation to prevent telecommunication and broadcasting devices (such as those that use an assigned frequency range for radio communication) and electrical/electronics devices from being interrupted, causing interference, or other similar problems. Frequency range assignment is critical for ensuring important radio communication (e.g. fire services or police radio) and TV broadcasting, and preventing radio interference.

The EMC standards play an important role in adjusting the frequency range assignment. Another purpose of the EMC standards is to protect electrical/electronics devices from being subject to various interferences (including lightning surges and static electricity) or damage, by minimizing hazards found in their operating environments.

Classification of the Standards

(1) International Standards: ISO, IEC/CISPR, etc.

(2) Regional Standards: EN, ASEAN, etc.

(3) National Standards: JIS, BS, ANCI etc.

(4) Industrial Standards: JEITA, SEMI, etc.

(5) Form Standards: Bluetooth, USB, HDMI, etc.

The important thing to note is that international standards are developed by the organizations that meet the commercially agreed principles of the WTO (World Trade Organization) (i.e. to ensure transparency, openness, impartiality and consensus, effectiveness and relevance, coherence, and to address the concerns of developing countries). These above mentioned organizations include ISO, IEC, and ITU. Regional standards are developed to ensure impartiality in trade, imports and exports to/from the relevant region. The EN standard is a typical example. National standards are established when a country needs to have customized standards that suit the actual situation in the country. Such national standards may be incorporated in laws and regulations, and operated along with penalties. Industrial standards may define codes and standards for issues such as inter connectivity between devices. Usually, these codes and standards do not involve legal actions. The USB and HDMI standards are famous examples. It is important to note that the compliance with the standards is related to commerce and trade issues. Consequently the systems to ensure measurement methods and accuracy (e.g. ISO 17025: management system of testing and calibration laboratories) play as important a role as the designated limit values and frequency ranges in the operation of these standards. The standards and operating rules are created and operated globally. This movement is based on the idea that “radio waves used as the means of information-communication play an extremely important role in the fields of national security, economic activity, and social activity.”

Read our Blog: What is EMC ? Complete overview by an EMC expert in 2023

IEC Standards

The major international standards for the EMC sector are IEC (International Electrotechnical Commission) standards and CISPR (Comité international spécial des perturbations radioélectriques) standards. In the U.S., IEEE standards are more popular and used as the international standards in the field, e.g. antenna calibration tests. The procedures for establishing an IEC or CISPR standard include a conference of representatives from various countries. An IEC or CISPR standard is usually reviewed and revised once every 5 years, in order to keep its technological level equal to the current situation.

Hierarchy of Standards

Most international standards such as IEC are maintained systematically.

For example, EMC standards are systematized as follows: 

1.  Basic EMC publications/Technical report:
   These standards describe the general EMC specifications that are not limited to specific product or product families. (e.g. Terms: IEC61000 series, CISPR16)
2. Generic EMC standards:
   These standards are applied to products that are not subject to any specific product/product family EMC standards. (e.g. IEC61000-6 series)
3.  Product family EMC standards:
   The standards comprehensively applied to similar products are referred to as product family EMC standards. These standards define test, operating, and installation conditions, and so on.
4.  Product EMC standards:
   The standards applied only to the specific product are referred to as product EMC standards.

The standards of (4) have the highest priority and those of (1) have the lowest priority. Products are required to comply with the standards according to this priority.

CISPR Standards

The CISPR standards are employed as national standards in various countries, and considered to be the global standard. Japan is way behind in shifting to international standards as compared with other countries.

For example, JIS standard may still be based on CISPR standard of 10 years ago. In the future, Japan needs to employ the international standards pro actively to take advantage of them to help in trade negotiations, to further her international contributions, and help solve environmental problems, and thus play a leading role in Asia. Table 1 shows a list of CISPR standards. If you check this list considering the above mentioned standard system, you will see that some of these standards assume state-of-the-art products with future technologies.

Below is a compilation of CISPR standards along with recent updates. However, it's important to note that this list is not the definitive and official version. For the most current and authoritative information, always refer to the official publications of the International Electrotechnical Commission (IEC)

Table 1. List of CISPR standards