What are ferrite beads?

Ferrite beads, or ferrite chokes, are electrical passive components designed primarily to constrict high-frequency signals. The ferrite has a specific frequency range over which it becomes resistive. Thus the ferrite beads constrict signals with frequencies over the intended range by absorbing the noise energy as heat. 

Ferrite beads typically remain connected with the power supply rail in the form of a series. Capacitors often remain combined with the beads as well. This generates a low-pass filter which reduces the noise from high-frequency signals. 

Types of ferrite beads

Ferrite beads are available in two major types of categories. These include:

High-Q ferrite beads

These types of ferrite beads are only used as resonators. High-Q ferrite beads aren't designed to be used in power isolation circuits.

Low-Q ferrite beads

These types of ferrite beads are also known as absorptive beads. Low-Q ferrite beads are primarily used for absorbing noise currents and are ideal filter networks. 

Applications

Ferrite beads are used extensively across electronics and electrical industries. The most common applications include:

• Reducing high-frequency signals
• Elimination of EMI noise
• Consumer electronics like mobile phones
• Computers and laptops
• Audio and video players
• TV tuners
• DVDs
• Gaming systems