Diff Ferrite bead and Inductor

[kil]

difference between ferrite bead and inductor

Hi All,

Whats the Difference between Ferrite Bead and the indcutor. When we use ferrite bead and when we use Inductor for Noise Filtering.

Thanks
KIL

 

[Awarapunshee]

difference between inductor and ferrite bead

A Ferrite bead is a dowel-like device which has a center holes and is composed of ferromagnetic material. When placed onto a current carrying conductor it acts as an RF choke. It offers a convenient, inexpensive, yet a very effective means of RF shielding, parasitic suppression and RF decoupling.

The most common noise generating suspects in high frequency circuits are power supply leads, ground leads and connections, and inter stage connections. Adjacent leads and unshielded conductors can also provide a convenient path for the transfer of energy from one circuit to another. A few ferrite beads of the appropriate material placed on these leads can greatly reduce or completely eliminate the problem. Best of all, they can be added to most any existing electronic circuit.

The amount of impedance is a function of both the material and the frequency, as well as the size of the bead. As the frequency increases, the permeability declines causing the losses to rise to a peak. With a rise in frequency the bead presents a series resistance with very little reactance. Since reactance is low there is little chance of resonance which could destroy the attenuation effect. Impedance is directly proportional to the length of the bead, therefor impedance is additive as each similar bead is slipped onto the conductor. Since the magnetic field is totally contained within, it does not matter if the beads are touching or separated. Ferrite beads do not have to be grounded and they cannot be detuned by external magnetic fields.

 

[Pardeep-singh]

Re: difference between inductor and ferrite bead

A Ferrite bead is a dowel-like device which has a center holes and is composed of ferromagnetic material. When placed onto a current carrying conductor it acts as an RF choke. It offers a convenient, inexpensive, yet a very effective means of RF shielding, parasitic suppression and RF decoupling.

The most common noise generating suspects in high frequency circuits are power supply leads, ground leads and connections, and inter stage connections. Adjacent leads and unshielded conductors can also provide a convenient path for the transfer of energy from one circuit to another. A few ferrite beads of the appropriate material placed on these leads can greatly reduce or completely eliminate the problem. Best of all, they can be added to most any existing electronic circuit.

The amount of impedance is a function of both the material and the frequency, as well as the size of the bead. As the frequency increases, the permeability declines causing the losses to rise to a peak. With a rise in frequency the bead presents a series resistance with very little reactance. Since reactance is low there is little chance of resonance which could destroy the attenuation effect. Impedance is directly proportional to the length of the bead, therefor impedance is additive as each similar bead is slipped onto the conductor. Since the magnetic field is totally contained within, it does not matter if the beads are touching or separated. Ferrite beads do not have to be grounded and they cannot be detuned by external magnetic fields.

Sir , u have told about only ferrite bead but havn't told any ing about difference in inductor and ferrite beads.

so, please provide that also

 

[vimalkhanna]

Use a multibore ferrite bead and make two /three loops of the wire .
The inductance is magnified and we get better filtering with the same capacitance

 

[bert_kak]

Re: difference between ferrite bead and inductor

Hi All,

Whats the Difference between Ferrite Bead and the indcutor. When we use ferrite bead and when we use Inductor for Noise Filtering.

Thanks
KIL

Inductor opposes current change & block AC signals. Ferrite beads suppress high frequency signals. Normally you use inductor in any power output especially switching regulators to separate the AC & DC signals then take advantage of opposing the current change in the circuit. you use ferrite bead when you want to separate two circuitry especially when application of certain circuit is high frequency. Hope this helps.

 

[FvM]

I think, saying a ferrite bead is a lossy inductor answers the question completely. Typically ferrite bead specifications also involve an inductance value in the lower range and larger tolerances. And it's mostly specified by an impedance rather than an inductance value.

Although the term ferrite bead traditionally refers to a small cylinder with a bore, it's today used for multilayer chips as well.

 

[vimalkhanna]

Feed thru filtering and parasitic suppression are optimum uses for the ferrite beads .I have applied many other ideas but this is best .The same was also used for making a PIE filter at DC input stage to give RFI/EMI filtering for my DC converter input switching at 1MHz.
It worked to 53dB levels .