36A SMD common-mode choke for reflow soldering

“Customers who prefer reflow soldering but need high-current common-mode chokes can now get an SMD solution,” according to the company. “These components can filter common-mode noise for rated currents from 24 A to 36 A at a temperature of +70°C. With additional cooling higher currents can be achieved – this is easy to implement as the top side can serve as a direct interface for a heat sink.”

Part numbers are of the form B82725Sxxxx040 (see table below), and the company is branding the parts ‘SurfIND’.

Operation is at up to 250Vac and there are seven nominal inductances across 120 to 820µH. Rated inductance drops by less than 10% at rated current (dc magnetic bias at +20°C). “With stray inductance of up to 1% of the nominal inductance, these chokes also dampen differential-mode noise,” said TDK.

Typical resistance ranges from 0.78 to 2.21mΩ depending on the part, footprint is always 40 x 38mm, and they are either 20.7 or 22.3mm high.

Construction is an epoxy coated ferrite core mounted on a plastic baseplate – all UL 94 V0 approved. “The design of the connection wiring eliminates the need for adhesives, while self-leading SMD leads ensure easy reflow soldering to PCBs,” said TDK.

All meet IEC/EN 60938-2.

Reflowable common-mode chokes will find use in telecom equipment sandwich packages, said the company, as well as industrial variable-frequency drives.

Further information on the products can be found at www.tdk-electronics.tdk.com/en/SurfIND

Yesterday, distributor TTI introduced a series of single and three-phase through-hole common-mode chokes that have nanocrystaline cores to reduce their size