TDK Introduces SMD Common-Mode Chokes Rated for Up to 80 V/35 A in a Compact PCB Footprint

TDK Corporation has introduced the EP21 series of flat-wire double chokes, components designed to filter out common-mode electromagnetic interference (EMI), the type of electrical noise that appears identically on multiple conductors at once and tends to radiate outward, causing interference with nearby circuits. A common-mode choke works by canceling out that shared noise while letting the actual intended signal pass through undisturbed.

The new series comes in a surface-mount (SMD) format measuring just 23.8 x 17.7 mm, with a height of 21.6 to 22.3 mm. To keep the footprint on the circuit board as small as possible, the components use underbody termination, meaning their connection points sit underneath the component itself rather than extending outward, and they use a four-pin design intended to improve mechanical reliability. TDK positions these chokes for use in applications like DC-DC converters or other low-voltage circuits that need EMC protection, shielding against electromagnetic interference more broadly.

On specifications, the EP21 series is rated for 48 V AC or 80 V DC, with rated current ranging from 20.3 to 35 A, and it can handle these ratings without derating, meaning without needing to reduc...