TDK presents SMD common-mode chokes for up to 80 V/35 A with a minimized PCB footprint

July 23, 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.

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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