Basics of EMC Standards

Introduction to EMC Standards

When we want to bring an electrical or electronic device to market, there are important rules we need to follow. These are called EMC standards, and they apply when we're creating, designing, and manufacturing the device. These standards basically establish 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 just making sure our device doesn't cause problems for other devices that communicate using electromagnetic signals.

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/electronic devices from being disrupted, generating interference, or causing other similar problems. Frequency range assignment is critical for protecting important radio communication (e.g., fire services or police radio) and TV broadcasting, and preventing radio interference.

EMC standards play an important role in adjusting frequency range assignments. Another purpose of EMC standards is to protect electrical/electronic devices from being subjected to various forms of interference (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, and coherence, and to address the concerns of developing countries). These 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 into laws and regulations, and operated along with penalties. Industrial standards may define codes and standards for issues such as interconnectivity between devices. Usually, these codes and standards do not involve legal actions. The USB and HDMI standards are well-known examples. It is important to note that compliance with 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

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. IEEE standards are more popular in the United States and are used as international standards in the field of, 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 five years, in order to ensure that its technological level is up to date.

Hierarchy of Standards

Most international standards are maintained systematically.

For example, EMC standards are systematized as follows: 

1.  Basic EMC publications/Technical report:
   These standards describe general EMC specifications that are not limited to specific product or product families. (e.g., IEC/TR 61000 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., IEC 61000-6 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.
4.  Product EMC standards:
   The standards applied only to a specific product are referred to as product EMC standards.

Standards in the (4) category have the highest priority, and those in the (1) category have the lowest priority. Products are required to comply with standards according to this priority.

CISPR Standards

The CISPR standards are employed as national standards in various countries, and are considered to be the global standard. Table 1 shows a list of CISPR standards.

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