See which Magnetics® Powder Core products are right for you
Magnetics® Powder Core products Kool Mu®,
XFlux® and AmoFlux®materials are distributed air
gap cores primarily used in power inductor
applications, specifically in switched-mode power
supply (SMPS) output filters, also known as DC
inductors. Other power applications include
differential inductors, boost inductors, buck inductors,
and flyback transformers.
These powder cores possess many outstanding
characteristics – high resistivity, low hysteresis and
eddy current losses, and excellent inductance stability under both DC and AC conditions.
They are not pressed with an organic binder, so do not exhibit any thermal aging effects,
as observed with powdered iron cores.
All Magnetics powder core materials are used in inductors, but each has its own
advantages:
• For reasonably low losses and reasonably high saturation at a low cost, Kool
Mu should be used since it has the lowest material costs.
• XFlux offers a more economical, high saturation material (1.6 T) for use in low and
medium frequency inductors and chokes. Its high saturation is advantageous in
applications where inductance under load is critical.
• The combination of high DC bias and low core loss density makes AmoFlux the
optimal solution for high-efficiency, high-power inductors.
Kool Mu® cores
Magnetics Kool Mu cores are made from 85% iron, 9% silicon and 6% aluminium alloy
powder for low losses at elevated frequencies.
They are naturally suited for the energy storage filter inductors used in switch-mode power
supplies. The 10,500 gauss saturation level of Kool Mu cores provides a higher energy
storage capability than can be obtained with gapped ferrites of the same size and effective
permeability.
Where significant ripple may contribute to heat rise, Kool Mu cores perform better than
powdered iron cores in these respects. In similar applications, it is possible that Kool Mu
cores will offer a reduction in core size over powdered iron cores.
Kool Mu cores are ideal for in-line noise filters where the inductor must support large AC
voltage without core saturation occurring. Line filters using Kool Mu cores can be smaller
in size, requiring fewer turns than by using ferrite cores. Kool Mu cores are also near zero
in their magnetorestriction coefficient, meaning that they are extremely quiet when
operating with audible frequency range noise or line current.
The high flux density and low core losses make Kool Mu cores excellent for use in power
factor correction circuits as well as unidirectional drive applications such as pulse
transformers and flyback transformers.
Features
• High saturation.
• Lower core loss than powdered iron.
• Moderate cost.
• Low magnetostriction.
• Very high Curie temperature.
• Stable performance with temperature.
• Variety of shapes available (E cores, U cores, blocks, segmented cores, etc).
XFlux® cores
XFlux cores offer an economical high saturation (1.6 Tesla) solution for use in low- and
medium-frequency inductors and chokes. The high saturation is advantageous in
applications where inductance under load is critical such as inverters for renewable energy
and Uninterruptable Power Supplies (UPS).
XFlux distributed air gap cores are made from 6.5% silicon iron powder. A true hightemperature material, with no thermal aging, XFlux offers lower losses than powdered iron
cores and superior DC bias performance. The soft saturation of XFlux material offers an
advantage over ferrite cores.
XFlux can be a lower cost alternative to High Flux, in situations where the higher core
losses of XFlux are acceptable.
Features
• Composition 6.5 SiFe alloy.
• Saturation flux density 1.6 Tesla.
3
• Typical core loss (50kHz,100mT) 650 mW/cm .
• Curie temperature 700°C.
• Operating temperature range -30°C to 200°C.
AmoFlux® cores
The core loss density of AmoFlux is significantly lower than High Flux, which allows for a
more efficient design with less temperature rise. Magnetics Molypermalloy Powder (MPP)
material has the best core loss density of the available powder core materials and
AmoFlux is only 20% higher. The DC bias of AmoFlux is similar to High Flux and superior
to both MPP and Kool Mu. Better DC bias will allow higher current handling in the same
size core or a smaller size core to be used to achieve the same target inductance.
This combination of high DC bias and low core loss density makes AmoFlux the optimal
solution for high efficiency, high power inductors. Since AmoFlux is a powder core, it has
the soft saturation characteristic as our other powder cores.
See all of our Magnetics range