Keep the system as low as possible

In fact, the global EMI/RFI filter Market, currently worth approximately $850 million, is expected to grow to nearly $1.1 billion by 2027, with a compound annual growth rate of 3.56% over the period, according to a Research report by Verified Market Research. As the trend towards digitization and electrification in industries such as manufacturing and automotive accelerates, EMI/RFI filters are likely to become increasingly diverse in their range of applications.

Considerations for EMI filter design

So, before evaluating the performance of some of the latest devices on the market, let's first take a closer look at the role of EMI filters. In general, EMI/RFI filters prevent interference on the signal or power cord that could seriously affect the device or the circuits in the device, affect the performance of the device or ultimately lead to complete failure. EMI/RFI filters primarily prevent interference by blocking higher frequency electromagnetic noise while allowing the desired lower frequency signals to pass through.

These components also help manufacturers meet stringent electromechanical compatibility standards around the world, limiting the noise emitted by equipment to AC grids. This mechanism works for almost any device that uses alternating current, from industrial machinery to medical and commercial equipment (such as ATMs) to small white goods (such as coffee machines). Therefore, EMI filters can be said to be ubiquitous and vital to ensure system performance.

Higher density component

Historically, one of the most common and efficient EMI filter types is the common-mode choke. Typically, these devices feature conductor windings coupled together by a ferrite core. Common-mode ring chokes have a variety of characteristics, usually with nanocrystalline metal core design, and can be used in a variety of noise prevention fields.

However, with the rapid development of technology, plastic shell filters that meet the requirements of single-phase EMC have recently come to the fore. Most of these latest generation devices employ patented improvements in soft nanocrystalline materials that enable the generation of more optimized cores that can provide some unique performance benefits.

More notably, these nanocrystalline materials have higher permeability and lower losses than the ferrite variants found in conventional EMI filters. Compared to other EMI filters previously available in the market, it can achieve a more compact and higher density design, resulting in higher attenuation capacity and smaller package size.

Some nanocrystalline core-core devices are very small, including magnetic elements and capacitors, with some devices as small as 75 x 44 x 25 mm, making them 20 to 60 percent smaller than competing filters with ferrite cores, but still able to provide superior attenuation performance. These features are very valuable to design engineers because they help meet the consistent trend of miniaturization of electronic devices.

In addition, ferrite materials with higher permeability are effective in the low frequency range, while those with lower permeability are effective in the high frequency range. But the latest generation of metal nanocrystal materials is effective in both low and high frequency broadband frequency ranges, and thus can provide a highly flexible solution.

EMI filter innovation technology

So, how are these R&D activities reflected in the innovation of new filter products? As shown in Figure 1, the latest single-phase filters provide design engineers with excellent noise attenuation performance in small, lightweight packages. The filter can be rated for voltages up to 250 VAC, frequencies of 50 or 60 Hz, and current ratings ranging from 6 to 30A. Typically, they are packaged in a housing with screw terminals to provide convenience and flexibility when wiring.

                                                  

                                                                            KEMET's GTX series filter

Newly introduced devices include multiple Y-class capacitor combinations that handle different frequencies and support a variety of inverter topologies, with combination options that have Y-class capacitors on both input and output. These compact components operate in temperatures ranging from -25 ° c to 55 ° C and are UL, C-UL, and TUV certified to meet RoHS standards.

The performance parameters of multiple types of components mean that the latest single-phase filters are widely used in various fields. For example, in the field of industrial equipment, they can be used in general purpose inverters, factory automation, machine tools and welders, among others. Meanwhile, in medical devices, they have been used in a range of diagnostic equipment and even massage chairs.

GTX series applications

KEMET's GTX series provides a compact, lightweight solution for suppressing electromagnetic noise over single-phase voltage lines  

                

                                                    Diagram of the internal circuit of the GTX filter

High attenuation performance for specific noise frequencies can be achieved by selecting from 30 product variants according to rated current and desired Y capacitor mode

               

                                               Example attenuation diagram of GTX-2060***. (Grade 6A)

For example, the GTX-2060*** is rated for 6A current and can be selected from a variety of Y capacitor configurations. In applications requiring a 6A rating, peak attenuation for YXX models is about 500 kHz, Y22 about 1 MHz, Y0X about 10 MHz, and so on.

EMI/RFI filtering technology innovation

There has been a high level of innovation in EMI/RFI filtering technologies, much of which has resulted from collaborative research and development efforts in recent years, leading to new products for suppressing conducted noise from single-phase voltage lines. By employing advanced nanocrystalline core materials, these filters are able to achieve excellent attenuation characteristics in compact plastic enclosures, and the integrated Y-capacitor combination provides high flexibility for all applications.

In short, this innovation, combined with other available products, ensures that EMI/RFI noise is always controlled, while providing design engineers with the flexibility they need.