0199000019 Fair-Rite, 0199000019 Datasheet - Page 137

• Manufacturer Part Number: 0199000019
• Description: BEAD KIT, EMI SUPPRESSION
• Manufacturer: Fair-Rite

Specifications of 0199000019

• Kit Contents: Contains 28 Different Beads In Three Suppression Materials, 73, 43 And 61.
• Component Type: Shield Bead Kit
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

F a i r- Rite Products Co r p.
Phone:
Technical Information
Low and Medium Frequency
Broadband Transformers
For broadband transformer applications the optimum ferrite is
the material that has the highest initial permeability at the lower
cutoff frequency f
or 78 material, are very suitable for low and medium frequency
broadband transformers designs. As stated before, the trans-
former parameter that is most critical is the shunt reactance (� L ),
which will increase with frequency as long as the material
permeability is constant or diminishing at a rate less than the
increase in frequency. This holds true even if a transformer is
designed using a manganese zinc ferrite where f
end of the flat portion of the permeability vs. frequency curve.
Although the whole bandpass lies in the area where the initial
permeability is decreasing, yet the bandpass characteristics will
be virtually unaffected. For broadband transformers that use a
manganese zinc ferrite material the core geometry should be
such as to minimize the R
resistance to the inductance for a single turn should be a
minimum. The range of pot cores, standardized by the Interna-
tional Electrotechnical Commission in document IEC 60133, has
been designed for this minimum R
such as the E cores and toroids can also be used in the design
of these broadband transformers. Often the final core selection
will also be influenced by such considerations as ease of
winding, terminating and other mechanical design constraints of
the transformer.
Broadband Transformers with a
Superimposed Static Field
In transformer designs that have a superimposed direct current,
gapped cores can be employed to overcome the decrease in the
shunt inductance. Hanna curves can be used to aid in the design
of inductive devices that carry a direct current. For more informa-
tion see section “The Effect of Direct Current on the Inductance
of a Ferrite Core” on page 130.
High Frequency Broadband Transformers.
Although there is no clear division between the frequency
regions, for this article it is assumed that the high frequency
broadband transformer designs use nickel zinc ferrites as the
preferred core material. This will typically occur for transformer
(888) FAIR RITE / [phone] • FAX: (888) FERRITE / [phone]
[phone]
1
. Manganese zinc ferrites, such as Fair-Rite 77
dc
/L ratio. In other words, the ratio of dc
dc
/L ratio. Other core shapes
1
(888) 337 -7483
is at the higher
designs where the bandpass lies wholly above 500 kHz. At these
higher operating frequencies it becomes more important to
consider the complex magnetic parameters of the core material,
rather than use the simple core constants, such as A
mended for low frequency designs.
Another important consideration is that high frequency trans-
formers are generally used in low impedance circuits, which
means that these designs require low shunt impedances. This
can often be accomplished with a few turns, hence winding
resistances are no longer an issue, and the design concept of
minimizing R
become focused on core shape and material for the required
shunt impedance at f
of the winding. Since the material characteristics permeability
and losses affect the shunt impedance these parameters need
to be considered in high frequency broadband transformer
designs. Figures 4, 5 and 6 are typical curves of impedance Z ,
equivalent parallel reactance X
resistance R
on the same multi-aperture core 28—002302, in 73, 43, 61 & 67
material, wound with a single turn through both holes. For high
frequency broadband transformers the toroidal core shape
becomes an attractive core geometry. The few turns that are
often required can easily be wound on the toroid. However,
windings that require only a few turns may give rise to problems
in obtaining the desired impedance ratios.
leakage inductance it is suggested that the primary and sec-
ondary windings be tightly coupled and where possible a
bifilar winding be used.
An improvement in core performance over toroids can be
obtained by the use of multi-aperture cores, which can be
considered as two toroidal cores side by side. This core shape
has a lower single turn winding length than the equivalent
toroidal core with the same core constant C
a wider bandwidth of the transformer design. Many broadband
transformers have been designed utilizing nickel zinc ferrite
toroids with good results. If bandwidth requirements cannot be
met using toroids, multi-aperture nickel zinc cores should be
considered.
The multi-aperture cores listed in this catalog on page 44, are
available in the nickel zinc ferrite materials 67, 61 and 43 as
well as the manganese zinc ferrite 73 material.
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p
dc
as a function of frequency. They are measured
/L is no longer required. The design will instead
1
along with reducing leakage inductance
p
and equivalent parallel loss
1
, and will result in
To minimize
L
, recom-