Different Ferrite Designs for Effective EMI Suppression

Engineers count on cable ferrites or ferrite cores to dispel high-frequency electromagnetic interference (EMI) or radio frequency interference (RFI). Depending on the type and interference frequency, ferrite cores help in redirecting the EMI or radio frequency signals back down the cable, thus protecting devices from unwanted signals. Cable ferrites or ferrite beads used in keyboards, mouse, video, or any other secondary cables connected to computers provide maximum protection against interference. They are also used in power cables when an electronic device is powered from any external source. Different types of ferrite cores help in reducing harmful emissions from the cable and suppress high-frequency radiations in it. You can also use them to reduce or eliminate the unwanted noise signals that are more than 10 MHz. However, you must pick the right ferrite designs to provide maximum protection from EMI. Read on to learn about three popular types of EMC ferrites and where you should use each:

Snap Ferrites

Use snap ferrites if you are looking for retrospective fitting on prevailing cable lines. These products come with a unique lock that provides protection against an unwarranted opening. The plastic case further protects it from mechanical damage. The construction and design also provide greater contact pressure on the ferrite halves. This leads to outstanding inference suppression. The typical application uses are monitor leads, signal lines, data communication lines, mouse cables, and printed cables.

Ferrite Sleeves

Unlike snap ferrites that come with nylon clamps, people use ferrite sleeves or rings to place them on the cable before the final assembling. Once it’s done, designers secure it with the help of heat-shrink potting or tubing. This method is widely used in all computer monitors today. Make sure that the cable diameter matches closely with the inner diameter to provide maximum interference suppression. You can increase the inductive percentage through several windings. Increasing multiple windings helps in attaining better impedance.

Flat and Ribbon Cable Ferrites

If you are using applications where you require a longer ribbon cable and suppression of unwanted interference is still a necessity, flat or ribbon cable ferrites play a crucial role in meeting compliance guidelines. To adjust the flat wire optimally to the body, you will need three ferrite core shapes. For maximum EMI protection, you need to tie up the flat ferrites with a self-adhesive tape or plastic clips.

Six-Hole Ferrite Beads

The six-hole ferrite beads, also known as VHF chokes, have 2.5 windings. They have the capacity to resist high electricity levels over a long span of time without being saturated. People use these ferrite beads to attain maximum protection against radio frequency interference on circuit boards.

Cable ferrites offer maximum interference suppression, added isolation, and filtering in noisy digital environments. However, you must consider circuit characteristics and the type of interference you want to block using ferrite beads. Choose ferrite cores that are capable of protecting noise-sensitive analog devices or components. Consult an EMI shielding solution provider to select the right product.

Elvis Moore is an active blogger with an extensive industry experience in the field of electronics and technology.