July 27, 2026

TDK Corporation (TSE:6762) presents the EP21 series (ordering code: B82552J*J021) of flat-wire double chokes. These components are designed for common-mode EMI filtering and are available in an SMD format with dimensions of only 23.8 x 17.7 mm and heights ranging from 21.6 to 22.3 mm. To minimize board space, these components feature underbody termination. They can be used as common-mode chokes for applications such as DC-DC converters or other low-voltage EMC protection circuits. Their four-pin design enhances mechanical reliability.

They can handle rated voltages of 48 V (AC) or 80 V (DC) and rated currents of 20.3 to 35 A without derating up to +70 °C. However, if the temperature exceeds +70 °C, derating is required. The DC resistance is as low as 0.44 mΩ, while the rated inductance ranges from 160 to 640 µH, with an average stray inductance as low as 200 nH. Depending on the type, the maximum impedance occurs at frequencies between 500 kHz and 3 MHz.

Main applications

–  Common-mode chokes in DC-DC converters

–  Low-voltage EMC protection

Main features and benefits

–  High rated currents

–  High rated inductance

–  Low DC resistance

–  MnZn ferrite

–  Flat-wire winding

–  Surface-mount technology

–  Compact size due to underbody termination

About TDK Corporation

TDK Corporation (TSE:6762) is a global technology company and innovation leader in the electronics industry, based in Tokyo, Japan. With the tagline “In Everything, Better” TDK aims to realize a better future across all aspects of life, industry, and society. For over 90 years, TDK has shaped the world from within; from the pioneering ferrite cores to cassette tapes that defined an era, to powering the digital age with advanced components, sensors, and batteries, leading the way towards a more sustainable future. United by TDK Venture Spirit, a start-up mentality built on visions, courage and mutual trust, TDK’s passionate team members around the globe pursue better—for ourselves, customers, partners, and the world. Today, the state-of-the-art technologies of TDK are in everything, from industrial applications, energy systems, electric vehicles, to smartphones and gaming, at the core of modern life. TDK’s comprehensive, innovative-driven portfolio includes cutting-edge passive components, sensors and sensor systems, power supplies, lithium-ion and solid-state batteries, magnetic heads, AI and enterprise software solutions, and more—featuring numerous market-leading products. These are marketed under the product brands TDK, InvenSense, Micronas, Tronics, TDK-Lambda, TDK SensEI, and ATL. Positioning the AI ecosystem as a key strategic area, TDK leverages its global network across the automotive, information and communication technology, and industrial equipment sectors to expand its business in a wide range of fields. In fiscal 2026, TDK posted total sales of USD 16.6 billion and employed about 107,000 people worldwide.