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What does a ferrite choke do?
A ferrite bead (also known as a ferrite block, ferrite core, ferrite ring, EMI filter, or ferrite choke) is a type of choke that suppresses high-frequency electronic noise in electronic circuits.
What is a ferrite material?
Ferrite, a ceramic-like material with magnetic properties that are useful in many types of electronic devices. Ferrites are hard, brittle, iron-containing, and generally gray or black and are polycrystalline—i.e., made up of a large number of small crystals.
Where does the ferrite choke go?
Installing Ferrite Beads. Place the bead on the wire about 2 inches (5.1 cm) from the device. The bead should work regardless of its position on the wire, but it may work better at reducing RFI if placed closer to the source. It can even go up against the device without hurting anything.
How does a ferrite choke work on a power supply?
When a ferrite bead choke is placed on the power line connecting to an electronic device, it removes any spurious high frequency noise present on a power connection or that is output from a DC power supply. This ferrite clamp use is one of many approach to noise suppression, such as that from a switched-mode power supply.
How are ferrite bead chokes used in electronics?
Because ferrite bead impedance is inductive, ferrite bead inductors are used to attenuate high-frequency signals in electronic components. When a ferrite bead choke is placed on the power line connecting to an electronic device, it removes any spurious high frequency noise present on a power connection or that is output from a DC power supply.
Why is ferrite used to dissipate high frequencies?
Since ferrite materials are resistive at high frequencies, they primarily dissipate the absorbed energy as heat. This heat isn’t necessarily a problem for your PCB when a ferrite choke is used on a power supply line, but it can become one when it is used to dissipate high frequencies at high current.
How does a choke pick up common mode RF?
None of the conductors needs to be grounded for RF to pick up and/or radiate RF common-mode signals. A transmitting choke creates a high impedance in the path of common-mode (CM) RF current that a feed line would otherwise pick up from a transmitted signal. That interaction is called coupling, and blocking the current is called decoupling.