EN 55035 Electromagnetic Compatibility of Multimedia Equipment - Immunity Requirements

The European standard “EN 55035 Electromagnetic compatibility of multimedia equipment – ​​Immunity requirements” addresses the electromagnetic compatibility of multimedia equipment. This standard applies to multimedia equipment with a nominal AC or DC supply voltage not exceeding 600 V, as defined herein. Multimedia equipment with broadcast reception functionality and multimedia equipment with non-broadcast wireless interfaces are covered by this standard.

The main objectives of the EN 55035 standard are as follows:

• To define the requirements that provide sufficient intrinsic immunity for multimedia equipment to function as intended in an environment with a frequency range of 0 kHz to 400 GHz.
• Establishing procedures to ensure repeatability of tests and reproducibility of results.

This standard on the electromagnetic compatibility of multimedia equipment is useful for:

• Telecommunications companies
• Information technology companies
• Radio stations
• Television signal providers
• Digital signal processing industries
• Scientific laboratories
• Medical facilities

Electromagnetic compatibility is the ability of electrical equipment and systems to operate acceptably in electromagnetic environments by limiting the unintended generation, emission, and reception of electromagnetic energy that could cause undesirable effects. The EN 55035 standard provides information on multimedia equipment and immunity requirements.

The EN 55035 standard specifies test methods, test levels, product operating conditions, and evaluation criteria for multimedia equipment. This standard includes the requirements for multimedia equipment immunity testing, including a selection of applicable tests, degradation levels to be applied during testing, configuration, performance criteria, and other necessary details.

The EN 55035 standard helps ensure that multimedia equipment uses the recommended range and does not interfere with other multimedia equipment by monitoring immunity requirements.

In an age where multimedia devices are ubiquitous, from smart TVs and broadcast boxes to professional audio systems and game consoles, ensuring these devices can seamlessly withstand electromagnetic interference (EMI) is vital. The EN 55035 standard is a key standard that sets the benchmark for electromagnetic compatibility (EMC) immunity in multimedia equipment. This standard helps manufacturers demonstrate that their products will not degrade or malfunction when exposed to real-world electromagnetic disturbances.

The EN 55035 standard, adapted from the international CISPR 35, has become a cornerstone for compliance in the European market, particularly as multimedia technology blurs the lines between consumer electronics, information technology equipment, and broadcasting equipment.

Prior to the EN 55035 standard, EMC immunity tests for multimedia equipment were a mix of overlapping standards, leading to confusion and inefficiency. Manufacturers had to use multiple documents concurrently. For example,

• The EN 55020 standard focused on immunity for broadcast receivers and related equipment such as TV and radio.
• The EN 55024 (CISPR 24) standard focuses on targeted information technology equipment such as computers and peripherals.
• The EN 55103-2 standard was related to professional audio, video, and entertainment lighting systems.

This fragmentation meant unnecessary testing and inconsistent requirements across product categories. The EN 55035 standard unified these into a single, streamlined standard. Today, this standard has become the go-to standard for proving compliance with the EMC directive 2014/30/EU.

The EN 55035 standard applies to multimedia equipment rated for AC or DC supply voltages up to 600 V and covering a wide frequency range from 0 kHz to 400 GHz. Its primary purpose is to ensure intrinsic immunity, meaning the equipment can operate as intended without causing or being exposed to unnecessary interference in the electromagnetic environment.

This standard covers primarily the following products:

• Consumer electronics: TVs, set-top boxes, home theater systems.
• Information technology and broadcasting equipment: Laptops, monitors, routers, and studio mixers.
• Professional installations: Lighting controls and audiovisual systems.

EN 55035 essentially mandates a series of immunity tests to simulate electromagnetic threats. These are performed individually and in any order, with performance criteria defining their validity levels from transient impairment (recoverable without intervention) to complete failure.

Primary tests that meet basic, performance, and operational criteria (A, B, C, or D, where A is the most stringent) are as follows:

• Radio frequency (RF) electromagnetic fields: Simulates ambient RF fields from broadcasters or wireless devices. Frequency range: 80 MHz - 6 GHz. Basic levels: 3 V/m (80% AM modulation). Higher for critical functions.
• Electrostatic discharge (ESD): Mimics static shocks caused by human touch. Frequency range: contact/air discharge. Basic levels: plus/minus 8 kV contact, plus/minus 15 kV air. Should not cause permanent damage.
• Electrical fast transitions (EFT) / Bursts: Represent switching transitions in power/communication lines. Frequency range: 5/50 ns pulses. Base levels: plus/minus 2 kV in the AC mains, plus/minus 1 kV in signal ports.
• Surge Test: Tests resistance to surges caused by lightning. Frequency range, 1,2/50 μs waveform. Basic levels, plus/minus 1 kV between lines, plus/minus 2 kV between lines for grounding.
• AC/DC port immunity: Controls against disturbances via power lines. Frequency range 150 kHz - 80 MHz. Base level, 3 V (common/differential mode).
• Transmission immunity on telecommunication ports: Focuses on data/signal lines. Frequency range: 150 kHz - 80 MHz. Base levels: 3 V. Excludes high-speed digital interfaces.
• Voltage drops and interruptions: Evaluates behavior during power surges. Frequency range: 0 to 100 percent decrease. Base levels: 40 percent decrease for 5 cycles, complete interruption for 5 seconds.
• Magnetic fields at power frequency: For sensitive audio circuits. Frequency range 50/60 Hz. Basic levels, 3 A/m. Applicable to CRT-era equipment, less applicable to modern LCDs.
• Radiation immunity: Extended for broadcast receivers. Frequency range: 26 MHz - 1 GHz. Base levels: up to 10 V/m.

These levels are performance-based.

For many years, our organization, with its competent and experienced staff, has been understanding the needs of its customers, providing the advanced testing services they require, and assisting in the establishment, implementation, and improvement of management systems. Within this framework, we also provide testing services to businesses in accordance with the "EN 55035 Electromagnetic compatibility of multimedia equipment - Immunity requirements" standard.