APPLICATION NOTE
4
Figure 4: Simulation results for BEAD73_1
Model Ferrite Beads in PSpice- Approach 2
The second method of modelling a Ferrite Bead depends on its Physical core properties contribute to the
inductance/impedance:
K is the impedance scaling factor,
L is the bead length,
OD is the outside diameter of the bead in inches,
ID is the inside diameter of the bead in inches.
N is the number of wire turns on the bead.
Note: A bead measuring 0.43" x 0.2" x 0.08" (Len, OD, ID) was used as the standard bead to which all others
were scaled.
Ferrite bead's electrical properties can be modeled by a simple parallel L-R-C circuit. By properly picking the L, R,
and C components, a good fit can be made to the actual bead's performance. These are generally the only
components that need to be changed in the model to simulate different bead materials.
Here is an example ferrite bead model.
.SUBCKT BEAD_73 Z1 Z2
+ PARAMS:
+ ID_Bead=0.08
+ OD=0.2
+ L=0.43
+ N=1
* * Impedance multiplier * *
