2773021447 Fair-Rite, 2773021447 Datasheet - Page 171

• Manufacturer Part Number: 2773021447
• Description: EMI/RFI Suppressors & Ferrites LF Z=78OHM @ 25MHz
• Manufacturer: Fair-Rite

Specifications of 2773021447

• Shielding: Unshielded
• Test Frequency: 100 MHz
• Product: Ferrite Beads
• Impedance: 78 Ohms
• Operating Temperature Range: - 55 C to + 125 C
• Termination Style: Axial
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

14th Edition
P.O. Box J,One Commercial Row, Wallkill, NY 12589-0288
Phone: (888) FAIR RITE / [phone]
R
E
Figure 2 Lumped equivalent of a transformer.
Figure 3 Simplified equivalent transformer circuit
For other circuit parameters see Figure 2.
R
E
a
a
a
a
E
R
C
R
L
L
R
Secondary parameters reflected to the primary side.
C
R
L
R
l
l
p
a
2
2
b
a
1
1
1
p
2
' = secondary winding capacitance
' = resistance of secondary winding
' = secondary leakage inductance
' = load resistance
= source EMF
= source resistance
= primary winding capacitance
= resistance of primary winding
= primary leakage inductance
= open circuit inductance of primary winding
= shunt resistance that represents loss in core
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C
R
L
R
C
R
l
d
c
c
= L
1
1
= C
= R
l
1
1
1
L
+ L
+ C
+ R
p
L
L
L
p
l
l
2
l
1
2
2
'
'
'
L
R
l
2
p
'
R
p
C
R
C
d
2
2
'
'
R
b
'
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Ideal
Transformer
R
Ideal
Transformer
Technical Information
b
'
[phone]
Fair-Rite Products Corp.
primary reactance X
equivalent shunt loss resistance R
therefore be expressed in terms of the shunt inductance:
For most ferrite broadband transformer designs, the only ele-
ments that are likely to effect the transmission at the mid-band
frequency range are the winding resistances. The insertion loss
for the mid-band frequency region due to the winding resistance
may be expressed as:
In the higher frequency region the transmission characteristics
are mainly a function of the leakage inductance or the shunt
capacitance. It is often necessary to consider the effect of both
of these reactances, depending upon the circuit impedance. In
a low impedance circuit the high frequency droop due to leakage
inductance is:
This high frequency droop in a high impedance circuit, due to the
shunt capacitance, is as follows:
Reviewing the insertion loss characteristics for the three fre-
quency regions, it can be concluded that the selection of ferrite
material and core shape should result in a transformer design
that yields the highest inductance per turn at the low frequency
cutoff f
low frequency region with the least number of turns. The low
number of turns are desirable for low insertion loss at the mid-
band region and also for low winding parasitics needed for good
response at the high frequency cutoff f
A
Where R = R
A
Where R
A
A
Note: (914) Area Code has changed to (845).
i
i
i
i
= 10 log
= 20 log
= 10 log
= 10 log
1
. This will result in the required shunt inductance for the
c
= R
10
10
10
10
a
1
x R
(
(
+ R
(
(
1+
1+
1+
1+
b
’ / R
LP
2
(
’
R
(
R
(
ω
ω
a
with a negligible contribution of the
a +
R
R
ω
+ R
a
L
L
c
R
= R
CR
p
l
b
b
(
’
’
(
2
(
b
2
’
(
(
dB
(
2
dB
(
p
. The insertion loss may
dB
dB
2
.
171