Ferrite Beads also known as ferrite chokes are passive devices and they are used to constrict high-frequency signals in electronic components. The ferrite becomes resistive over its intended frequency range and uses up the noise energy in the form of heat.
How do the ferrite beads work?
The ferrite bead is connected in series with the power supply rail and is often combined with the capacitors to ground on either side of the bead. This then forms a low-pass filter network, further reducing the high-frequency power supply noise. Use SPICE (Simulation Program with Integrated Circuit Emphasis) or another similar tool to ensure any anti-resonance peaks caused by ferrite or PCB inductive structure does not violate the target impedance limit....
Ferrite Beads come in two categories:
High-Q Beads - typically used as resonators and must not be used in power isolation circuits
Low-Q Beads - these are also called absorptive beads and they are lossy and make good filter networks because they are designed to absorb high-frequency noise currents and dissipate it as heat
What to consider when choosing Ferrite Beads?
Make sure that any voltage drop does not cause the target supply rail to fall below the recommended operating conditions of the device
The ferrite bead is inductive, therefore do not use it with High-Q decoupling capacitors
Applying ferrite beads correctly can be an effective and inexpensive way to reduce high-frequency noise and switching transients
Where are Ferrite Beads used?
Eliminating high-frequency EMI noise on any circuit design
Ferrite core sample kits include a selection of differently sized ferrite cores for use with a wide variety of cables and connections. Ferrite cores are magnetic cores used in electronics to help with noise suppression....
Why are ferrite cores important?
Ferrite cores help to protect your transformer or inductor from EMI (electromagnetic interference) and RFI (radio frequency interference) and prevent interference from moving to a device or from a device. When a cable is passed through the core, the magnetic fields created by the cable are concentrated within the ferrite core and converted to heat; the ferrite in turn dissipates the heat.
Types of ferrite core in ferrite core sample kits
Ferrite cores that are smaller in size and handle higher frequencies are used in signal transformers. Larger ferrite cores with lower frequencies are used in power transformers. Because of their comparatively low electrical conductivity, ferrite cores are also used in the cores of RF (radio frequency) transformers.
Ferrite rings are toroidal (doughnut) shaped, or cylindrical shaped pieces of ferrite (a ceramic compound).What do they do?Ferrite rings help to protect against EMI (electromagnetic interference) and RFI (radio frequency interference)....
They prevent interference moving to a device or from a device.How do they work?Ferrite rings can suppress noise without grounding. Ferrites are able to attract magnetic flux. When a cable is passed through the ring, the magnetic fields created by the cable are concentrated within the ferrite ring. This magnetic energy is converted to heat and the ferrite dissipates this by magnetic loss.How are they used?Ferrite rings can often be seen with cables threaded through them. They are common place in electronics to help with noise suppression. The cable can also be wrapped about the ferrite ring numerous times. Ferrite rings can be incorporated into broadband transformers, pulse transformers and common mode chokes.
Ferrite rods are cylindrical rods of ferrite (a ceramic compound).What do they do?Ferrite rods help to protect against RFI (radio frequency interference) and EMI (electromagnetic interference). They prevent interference moving to or from devices....
How are they used?Ferrite rods are designed for noise suppression and are frequently used in antenna and RFID applications. They can also be incorporated into ferrite core chokes, and broadband transformers.
Ferrite sleeves, also known as ferrite beads, are non-conductive components used in electrical circuits to suppress or filter high frequency electromagnetic interference noise. They prevent electromagnetic interference to and from a device. ...
How do ferrite sleeves work?
If a device produces radio frequency energy, the conductive cable is used as an antenna to transmit the energy through the device. The ferrite sleeve or bead reduces the output of EMI from the device itself and prevents the cable from acting as an antenna for other sources of EMI, like household appliances.
Uses for ferrite sleeves
Ferrite sleeves are commonly found on data cables and medical equipment. They may be built in to the equipment or be separate items that can be clamped on to a cable. You may see larger ones on external cables, like on computer monitor cables, while smaller ones can be used internally in electrical circuits, on printed circiut boards (PCBs) for example. Ferrite sleeves are often needed for regulatory compliance.
Ferrite tiles, or amorphous magnetic seating, consist of thin sheets of ferrite – a ceramic-like material with magnetic properties. Ferrite tiles are useful in many types of electronic devices, such as transformersand inductorsto absorb electromagnetic radiation and suppress noise....
Features and benefits of ferrite tiles
Ferrite tiles work by absorbing electromagnetic radiation and utilising magnetic resonance loss. They're low cost, being made of mostly rusted iron (iron oxide), and are resistant to corrosion. Other features and benefits of ferrite tiles include:
They're stable, hard and difficult to demagnetise.
They can be made with both high and low coercive forces.
They have a high magnetic permeability and high electrical resistance.
They're flexible and easy to handle.
Applications of ferrite tiles
Ferrite tiles can used as a highly permeable thin magnetic core for inductors or transformers, or as shielding against leakage from coils of magnetic parts. They can also be used for applications where high noise suppression is needed in a broad frequency range.
Flat cable ferrite cores are made from the ceramic material ferrite and are used to eliminate noise on flat cables, such as flat ribbon cables. Ferrite cores help to prevent electromagnetic and radio frequency interference, which can otherwise cause problems for low-level signals....
Applications for flat cable ferrite cores
Flat cable ferrite cores are easy to attach to cables. You can simply thread the device over your cable and then apply the plug connectors that are usually provided. The ferrite core is held in position with heat-shrink sleeving, a metal clamp or adhesive tape, or you can glue it in place instead.
Flat cable ferrite cores are most commonly used in the cores of radio frequency transformers in applications such as switched-mode power supplies and ferrite antennas for AM radio receivers.
Features and benefits of flat cable ferrite cores
High magnetic permeability, which means they can support the formation of an internal magnetic field.
Low electrical conductivity, which helps to prevent eddy currents (loops of current induced within conductors by a changing magnetic field).