Choosing The Optimal Ferrite Material

Choosing the optimal ferrite material and magnetic material in general, it's made depending on the application.

Choosing the optimal ferrite material and magnetic material in general, it’s made depending on the application. There is a difference in the use of ferrite toroid for suppression of common monde currents and in the use of ferrite toroid for broadband impedance transformers. In general, for common mode transformers, number of turns wound on the toroid will change the usable frequency range.

General description of the applications in which ferrite materials are used:

Material	Common Mode Choke (CMC) -1 turn	Common Mode Choke (CMC) x turns	Impedance transformer(UN-UN)	BAL-UN 1:1
#31	3,5 - 100 MHz	1,5 - 50 MHz	-	1,5 - 30 MHz
#43	25 - 600 MHz	2 - 60 MHz	2 - 50 MHz	2 - 30 MHz
#52	150 - 1000 MHz	4 - 150 MHz	1 - 60 MHz	1 - 60 MHz
#61	200 - 2000 MHz	5 - 200 MHz	15 - 200 MHz	10 - 100 MHz
#77	200 kHz - 10 MHz	100 kHz - 10 MHz	0,5 - 8 MHz	1 - 8 MHz

#31 Material

Parameter	Symbol	Value	Units
Initial permeability	µi	1500
Flux density @ field strength	B H	3900 5	Gauss Oersted
Residual flux density	Br	3200	Gauss
Coercive force	Hc	0.28	Oersted
Loss factor @ specific freq.	Tan δ/ µi	20 1.0	10^-6 MHz
Temperature coefficient of initial permeability (20 -70°C)		1.6	%/°C
Curie temperature	Tc	>130	°C
Resistivity	ρ	3000	ohm-cm

#43 Material

Parameter	Symbol	Value	Units
Initial permeability	µi	800
Flux density @ field strength	B H	2900 10	Gauss Oersted
Residual flux density	Br	1300	Gauss
Coercive force	Hc	0.45	Oersted
Loss factor @ specific freq.	Tan δ/ µi	250 1.0	10^-6 MHz
Temperature coefficient of initial permeability (20 -70°C)		1.25	%/°C
Curie temperature	Tc	>130	°C
Resistivity	ρ	1×10^5	ohm-cm

#52 Material

Parameter	Symbol	Value	Units
Initial permeability	µi	250
Flux density @ field strength	B H	4200 10	Gauss Oersted
Residual flux density	Br	3300	Gauss
Coercive force	Hc	0.6	Oersted
Loss factor @ specific freq.	Tan δ/ µi	45 1.0	10^-6 MHz
Temperature coefficient of initial permeability (20 -70°C)		0.75	%/°C
Curie temperature	Tc	>250	°C
Resistivity	ρ	1 x 10^9	ohm-cm

#61 Material

Parameter	Symbol	Value	Units
Initial permeability	µi	125
Flux density @ field strength	B H	1500 15	Gauss Oersted
Residual flux density	Br	1000	Gauss
Coercive force	Hc	1.1	Oersted
Loss factor @ specific freq.	Tan δ/ µi	30 1.0	10^-6 MHz
Temperature coefficient of initial permeability (20 -70°C)		0.1	%/°C
Curie temperature	Tc	>300	°C
Resistivity	ρ	1×10^8	ohm-cm

#77 Material

Parameter	Symbol	Value	Units
Initial permeability	µi	2000
Flux density @ field strength	B H	5100 5	Gauss Oersted
Residual flux density	Br	1800	Gauss
Coercive force	Hc	0.25	Oersted
Loss factor @ specific freq.	Tan δ/ µi	15 0.1	10^-6 MHz
Temperature coefficient of initial permeability (20 -70°C)		1.2	%/°C
Curie temperature	Tc	>200	°C
Resistivity	ρ	100	ohm-cm