0

10

20

30

40

0.001

0.01

0.1

1

10

frequency [MHz]

- 40°C

+100°C

+120°C

+ 20°C

typical ferrite

CMC

VITROPERM

CMC

- 40°C

+ 20°C

+100°C

+120°C

0

10

20

30

0.01

0.1

1

10

100

frequency [MHz]

- 40°C

typical ferrite

+120°C

+150°C

+ 20°C

+160°C

VITROPERM

CMC

- 40°C

+ 25°C

+120°C

+150°C

+160°C

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0

100

200

300

400

500

600

Temperature [ °C ]

nanocrystalline

typical

Mn-Zn ferrite

-40%

-20%

0%

20%

40%

60%

80%

-40

-20

0

20

40

60

80

100

120

Temperature [°C]

nanocrystalline

! = 80 000

nanocrystalline

! = 30 000

typical MnZn ferrites

! = 5000 … 10 000

The saturation flux density of VITROPERM changes

by only a few percent in the operating temperature

range of up to 150 °C, while MnZn ferrites decline

up to 40 % at temperatures above 100 °C. The high

Curie temperature of VITROPERM alloys (above

600 °C), allows short term maximum operating tem-

The permeability of VITROPERM typically changes

by less than 10 % in the temperature range

from -40 °C to 120 °C, while the permeability of

MnZn ferrites can drift in a range of ± 40 – 60 %

around the room temperature value.

Fig. 10: Relative change of μT) at f = 100 kHz, normalized for room temperature

contact VAC for more detailed information.

Fig. 11b: Comparison of temperature dependence of insertion loss up to 160 °C of a

VITROPERM CMC and a MnZn choke using a high Curie temperature ferrite material

Fig. 11a: Comparison of temperature dependence of insertion loss of a

VITROPERM CMC and a choke with standard MnZn ferrite core

Insertion loss (and impedance) of a CMC made of VITROPERM 500F is almost temperature-independent in the tempe-

rature range of – 40 °C to above 150 °C. In contrast, ferrite chokes feature a significant drop of insertion loss with increa-

sing temperature.

Thermal

properties

Fig. 9: Temperature dependence of saturation flux density Bs(T)

8

NaNOcRysTallINE VITROPERM / EMc PROducTs