EMI Suppression Filters(EMC and Noise Suppression) Noise Suppression for Medical Devices

医療機器向け ノイズ対策

In 1979, Murata Manufacturing Co., Ltd. brought to the market the three-terminal capacitor DS310 ahead of its competitors in industry, and since then, it has maintained a constant position at the forefront of industry in developing EMI suppression products.
Based on the concept of proprietary product development, as a best solutions partner for customers in suppressing noise, it has also been committed not just to product development but also to the development of new technologies for noise suppression and the dissemination of these technologies.
Some medical devices differ from general household electric appliances in that they affect human life, so some devices require even more complete noise countermeasures. This page presents the strengths of Murata noise suppression products and Murata's varied expertise in this area, and introduces products suitable for medical devices.

Noise Suppression Issues in Medical Devices

Noise Countermeasure Issues in Medical Devices With high-grade medical devices, it is often the case that malfunctions, data corruption and other problems caused by the infiltration of noise from other devices is not allowed. For this reason, countermeasures for preventing both the generation and infiltration of noise are required on devices that are used in these instances. In particular, anti-noise measures are required over a wide range since it is impossible to identify where incoming noise is infiltrating from.

Strengths of Murata Noise Suppression Products

1.Murata’s EMC Support Setup

Murata Manufacturing Co., Ltd. has established two EMC support centers in Japan, Kyoto and Yokohama, and four of these centers in Greater China Beijing, Shanghai, Shenzhen, and Taiwan. These centers provide technical support to any customers who are looking for solutions to their noise-related problems.
Each center has the capabilities to provide the support described below.

Details of Murata’s EMC support setup

2.Core Technology

Murata’s three core technologies have been applied and the most suitable methods for applications have been selected to bring outstanding products to the market.

3.Market Performance

AV and household electrical equipment are increasingly becoming digitized, and the high-speed clock signals that flow internally through this kind of equipment sometimes adversely affect the equipment as electromagnetic noise. Noise suppression products prevent malfunctions, etc., caused by noise, and, at the same time, contribute to producing high image and sound quality in AV equipment. Murata’s chip EMI suppression filters account for a 35% share of the world market.
* World share is a value estimated by Murata and varies according to markets and applications.

医療機器向け ノイズ対策,EMI除去フィルタ世界シェア35%

Murata’s Noise Suppression Products

医療機器向け ノイズ対策

Chip Ferrite Beads(BLM Series)

Inductor type EMI suppression filters are effective in a range from several MHz to several GHz. They can be widely used for the suppression of relatively light noise as general-purpose noise suppression products. Although inductor type EMIFIL behaves at low frequencies as an inductor having slight inductance, it generates the impedance whose main constituent is a resistance component at high frequencies. When they are inserted in series in the noise conducting path, the conductance of noise is obstructed and absorbed by this resistance component.



Three-terminal capacitors developed for noise suppression are made by turning a three-terminal capacitor into a chip shape. The inside of these capacitors is configured like a feedthrough capacitor, and is designed so that the ground-side impedance is extremely small. Because of this structure, these capacitors are extremely effective in suppressing noise in the high frequency domains of several hundred MHz or higher.


Common mode choke coils (DLP/DLW/DLM/PLT Series)

Common Mode Choke Coils(CMCC) reduce the common mode noise that is problematic in differential transmission (examples: USB, HDMI and Mipi), balanced transmission, power supply lines, and audio lines. They are ideal for suppressing common mode noise with frequencies ranging from several megahertz to several hundred megahertz with no adverse effect on the signals (upper cut-off frequency).

DL-PL Series