Tmax =

μi=

15 000...150 000

4 000... 6 000

Max. operational temperature

Continuous-epoxy

Continuous-plastic casing

short-term

Permeability

VITROPERM 500F

VITROPERM 250F

Core losses (100 kHz, 0.3 T)

The superior material properties of nanocrystalline

VITROPERM enable common mode chokes with

high inductance/impedance with a small number of

turns, resulting in reduced copper losses, low win-

ding capacitance and excellent HF performance.

Due to the high initial permeability, low winding ca-

pacitance and a low Q-factor (above 100 kHz)

VITROPERM CMCs offer a broadband insertion loss

curve ranging from 10 kHz up to several MHz and

improved attenuation behaviour at both low and high

frequencies in comparison to conventional ferrite

chokes with similar core dimensions and identical

windings (see Fig. 13).

Better attenuation properties and an extended ope-

rating temperature range allow a reduction of the

component volume by a factor of up to 3 or more

under similar conditions. Note that the insertion loss

curve of the small VITROPERM choke in Fig. 14 is

similar to that of ferrite materials at frequencies of

about 600 kHz – 1 MHz and is superior below 500

kHz and above 1 MHz.

The excellent attenuation of VITROPERM CMCs

simplifies the filter design in a wide frequency range.

For laboratory tests, VAC offers different sample kits

with selected standard cores and chokes.

Fig. 13: Comparison of insertion loss curve of a VITROPERM 500F CMC (red curve) and ferrite CMC

(blue curve) of similar size and with the same number of turns.

Fig. 14: Comparison of the dimensions of a VITROPERM 500F CMC (red curve) and ferrite CMC

(blue curve) with similar attenuation properties in the 1 MHz range

design advantages

with

VITROPERM

Bs = 1.2 T

Hc < 3 A/m

≈115 μ cm

Tc > 600 °C

VITROPERM – typical data

Saturation flux density

Coercivity (static)

Saturation magnetostriction

VITROPERM 500F

VITROPERM 250F

Specific electrical resistance

Curie temperature

10

NaNOcRysTallINE VITROPERM / EMc PROducTs