We have more than 500 successful designs.
We always deliver the lowest lifetime cost for your component.
Our chokes modes are used in medical devices, aircraft, communications equipment, semiconductor processing equipment and test and measurement devices.
If you can’t find the common mode choke that is ideal for your application, we can design a custom common mode choke for you. Whether you need high attenuation in a small package, a specified creepage and clearance, or have a unique spec requirement we have a common mode choke design for you. Below is an example of one of our custom choke mode solutions.
A common mode choke is an essential component in most switch mode power supplies. Unlike a differential mode choke, a common mode choke is designed to pass differential mode current while blocking common mode noise. The windings of a common mode choke are connected out of phase so the impedance of the core is only seen by the common mode noise. A good common mode choke will deliver high attenuation of common mode noise in the frequency range of interest, typically 10 kHz to 10 MHz, and handle the full RMS power without overheating. Isolation is also an important design criterion for common mode chokes.
A common mode choke needs to have excellent noise attenuation over a wide frequency range, have low capacitive coupling, and handle your full load RMS current without overheating. Our standard product offerings provide great value with superior performance at a low cost. With hundreds of designs to our credit, if you don’t find what you are looking for our engineering team can take care of you. Whether it is more performance in a smaller package, higher power, higher attenuation, or a different package, we have you covered.
These are the largest nano-crystalline common mode chokes offered by West Coast Magnetics. They provide high attenuation levels at operating currents up to 52A. Utilizing nano-crystalline technology allows for more attenuation inside a smaller footprint; ferrite cores can not achieve the levels of attenuation offered by the WCM510 series. Contact West Coast Magnetics to speak with a knowledgeable engineer to determine which choke is right for your application.
WCM is pleased to announce the introduction of a standard product line of surface mount common mode chokes that utilize the high attenuation benefits of nano-crystalline material. These chokes can obtain minimum inductances up to 116mH while being able to handle up to 8.7A of current with reasonable operating temperature increases. There are three different form factors to choose, resulting in a tailored fit to your common mode noise attenuation application. All form factors are pick-and-place compatible to meet the high volume production demands. Please contact a knowledgeable engineer at West Coast Magnetics to discuss your application today!
2 mH SMD common mode choke: This compact design delivers very high impedance over a broad frequency spectrum in a compact SMD design. Based on WCM’s 504 series, this choke was modified to meet the demanding requirements of an automotive application. It will handle up to an amp of current, and much higher current for short durations. All materials are minimum class B, 130 C rated, and with 1500 Vac of isolation, this design passes most safety agency requirements
Using a ferrite core, this common mode choke has very high impedance and can handle 50 amps of RMS power. 2500 Vac of isolation and 3 mm of creepage and clearance put it in a category of passing regulatory agency requirements. The ferrite core is very affordable but if you want the same level of performance in a smaller package, we can substitute an even better core option. Contact WCM to discuss your options.
WCM508 series common mode chokes are designed specifically for very low-profile applications. With an rMs current rating of up to 30 amps, noise impedance in excess of 1000 ohms, and a height less than 1.4 cm, this common mode choke packs a lot of performance in a small package.
Click below to see more common mode chokes or call us at
Ask a Question