WAZIPOINT Engineering Science & Technology: What is Ferrite Bead?

Wednesday, March 1, 2023

What is Ferrite Bead?

A ferrite bead is an electronic filter circuit that is also known by many different names- a ferrite block, ferrite core, ferrite ring, EMI filter, or ferrite choke.

Interestingly is that most people who use laptops, computers, or similar electronic types of equipment are familiar with Ferrite Beads, we see them every day, but many of us do not know the name of this guy.

It looks a like short barrel at the end of old USB cables, data cables, etc.

Cable End and Ferrite Bead

Why Ferrite Bead uses in cables?

Ferrite Bead uses at the end of a USB cable to block the noises to enter the device or come out from the device to interfere with other electronic devices.  

A ferrite bead or a ferrite block is a type of choke or a passive device that filters high-frequency noise energy over a broad frequency range.  

A Ferrite Bead or a ferrite clamp improves the power supply directly to the connected device blocking the noises and surrounding devices not interfering. 

The advantages of ferrite beads

Ferrite Bead is a useful bead filter for EMIs because it supplies a clear signal to the circuit suppressing high-frequency noise. Also, connecting a ferrite bead noise minimizing or elimination is possible. 

The disadvantages of ferrite beads

Though a ferrite bead acts as a resistive load at a high frequency it can create a problem for the circuit. So, voltage and heat dissipation need to consider. Connecting to a higher voltage circuit this resistive load may be negligible, but in a low voltage circuit, it can operate of 2Vot that considerable to absorb energy as heat.

What is used to make Ferrite Beads?

Ferrite beads are made from an iron-based compound called ferrite. Depending on their uses ferrite beads may be of different shapes and sizes. 

Palomar Engineers described details about their permeability range from 20 to more than 15,000 in the Ferrite Toroid comparison table below in their article Ferrite Ring Toroid Specs.

Are all ferrite beads the same size?

No, all ferrite beads are not the same size. There are numerous variations of ferrite used in the construction of ferrite beads. Some are high loss, wide frequency, high frequency, low insertion loss, and others.

A wide range of sizes is available from 8mm to 60mm.

Generally, select the size of beads, like headphone cords, need a 3 mm (0.30 cm) bead. USB cables and network cables will need a 5 mm (0.50 cm) bead. Thicker computer or electronic cables will need a 7 mm (0.70 cm) bead.

What to consider to choose a ferrite bead?

Three things should consider selecting a ferrite bead:
  • DC resistance, 
  • AC impedance, and 
  • Bias current rating.

Ferrite Beads Equivalent Circuit

Ferrite Beads Equivalent Circuit

A ferrite bead can be converted as a simple component circuit diagram that consists of resistors, an inductor, and a capacitor, as shown in the Figure above. 

Where the Rbead resistor is connected in series with the equivalent impedance of parallel connected Cpar, Lbead, and Rpar. Linear and nonlinear lumped frequency-independent R, L, and C circuit elements are used to model the DC-bias dependency of the frequency response.

A ferrite bead is a passive device that filters high-frequency noise energy over a broad frequency range becomes resistive over its intended frequency range and dissipates the noise energy in the form of heat.

Ferrite Beads Sales Market to Huge Growth

The ferrite Bead is a small element but the sales market is not small, it is pretty large. Ferrite Beads in the car market are an important sale issue. Murata has introduced a series of chip ferrite beads with a 20A current rating, aiming them at the battery charging systems

Ferrite Beads Sales market, which helps business strategists to make the best investment evaluation, Some of the Major Key players are TDK, Murata, TAIYO YUDEN, Sunlord, Yageo, Chilisin, Microgate, Samsung, Bourns, Zhenhua Fu, Fenghua advanced, Würth Elektronik GmbH, Vishay, Tecstar, Laird, Max echo.

How to Use Ferrite Beads in Your PCB Design?
When you will do noise filtering circuit design and analysis of the nose characteristics, you can calculate an approximate value for the bead inductance and determine the resonant frequency cutoff. It will conclude you to design a ferrite bead filter circuit on PGB.

Ferrite Bead familiar products like- Ferrite Shielding Beads,  Ferrite Toroid Core, Ferrite Filter Core, Toroid Core, Surface Mount Ferrite Bead, etc.


  1. A Ferrite bead or ferrite choke is used to attenuate high-frequency electromagnetic interference (EMI) in a circuit. It works like a low-pass filter that allows only low-frequency signals to pass through a circuit and eliminates high-frequency noise. My Photo Collection

  2. Having read your article, I have gained a wealth of information. I appreciate you providing Electronic Cables Supplier such useful information. Keep up the good work.


Thank you very much to visit and valuable comments on this blog post. Keep in touch for next and new article. Share your friends and well-wisher, share your idea to worldwide.

You may like the following pages