This is the PDF file of catalog No.C31E-6
C31E6.pdf 01.5.29
On-Board Type (DC) EMI Suppression Filters(EMIFILr)
GHz Noise Suppression Chip Ferrite Beads BLM18H Series
0.4±0.2
2
The chip ferrite bead BLM18H series comprises ferrite
bead inductors in the shape of a chip. This inductor
generates a high impedance which at high frequencies
mainly consists of a resistance element. The BLM18H
series is effective in circuits without stable ground
lines because the BLM18H series does not need a
connection to ground.
1.6±0.2
0.8±0.15
s
Features
The BLM18HG, BLM18HD series has a modified internal
electrode structure, that minimizes stray capacitance
and increases the effective frequency range. Impedance
values of 1000 ohm can be attained at frequency of 1Ghz
and greater.
1. The BLM18HG, BLM18HD series is similar to the
exiting BLM at frequency below 100MHz, however at
1GHz the impedance is approx. 3 times larger.
2. The BLM18HG is intended for standard signal lines
as this series provides significant impedance across
a broad frequency range. The BLM18HD provides a
sharper roll-off after the cut off frequency,
therefore this series is ideal for high speed signal
lines.
3. The magnetic shielded structure minimizes crosstalk.
The BLM18HK series is chip ferrite beads for GHz range
noise suppression of digital interface.The BLM18HK
series has a modified internal electrode structure that
minimizes stray capacitance and increases the effective
frequency range.
Resistance especially grows in the lower frequency range,
therefore BLM18HK series cansuppress the ringing.
in mm
s
Features
1. The BLM18HK series is realized high impedance at 1GHz
and suitable for noise suppression from 500MHz to GHz
range.
2. The BLM18HK series is effective in suppressing the
ringing because resistance especially grows in the
lower frequency.
3. The magnetic shielded structure minimizes cross talk.
s
Applications
• Interface line of computer that has high-speed CPU &
high-speed bus and other digital equipment like HDD.
• Suitable for noise suppression from 500MHz to GHz
range.
55
0.8±0.15
This is the PDF file of catalog No.C31E-6
C31E6.pdf 01.5.29
Part Number
BLM18HD471SN1
BLM18HD601SN1
BLM18HD102SN1
BLM18HG471SN1
BLM18HG601SN1
BLM18HG102SN1
BLM18HK331SN1
BLM18HK471SN1
BLM18HK601SN1
BLM18HK102SN1
Impedance (at 100MHz)
(ohm)
470
±25%
(1000 ohm (Typ.) at 1GHz)
600
±25%
(1200 ohm (Typ.) at 1GHz)
1000
±25%
(1700 ohm (Typ.) at 1GHz)
470
±25%
(600 ohm (Typ.) at 1GHz)
600
±25%
(700 ohm (Typ.) at 1GHz)
1000
±25%
(1000 ohm (Typ.) at 1GHz)
330 (400 ohm (Typ.) at 1GHz)
470 (600 ohm (Typ.) at 1GHz)
600 (700 ohm (Typ.) at 1GHz)
1000 (1200 ohm (Typ.) at 1GHz)
Rated Current
(mA)
100
100
50
200
200
100
200
200
100
50
DC Resistance(max.)
(ohm)
1.20
1.50
1.80
0.85
1.00
1.60
0.50
0.70
0.90
1.50
Operating Temperature Range
(°C)
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
-55 to 125
2
s
Equivalent Cirucit
s
Impedance-Frequency (Typical)
BLM18HD Series
4000
3000
Impedance (Ω)
BLM18HD102SN1
2000
BLM18HD601SN1
BLM18HD471SN1
(Resistance element becomes dominant
at high frequencies.)
1000
0
1
10
100
Frequency (MHz)
1000 2000
s
Impedance-Frequency Characteristics
BLM18HD471SN1
2000
2000
BLM18HD601SN1
1500
Impedance (Ω)
Impedance (Ω)
1500
Z
Z
1000
1000
R
500
X
X
500
R
0
1
10
100
Frequency(MHz)
1000
2000
0
1
10
100
Frequency(MHz)
1000
2000
BLM18HD102SN1
4000
3000
Impedance (Ω)
2000
Z
1000
X
R
0
1
10
100
Frequency(MHz)
1000
2000
56
This is the PDF file of catalog No.C31E-6
C31E6.pdf 01.5.29
EMI Suppression Effect
!Noise
Suppression in UHF Range
Noise Suppression Effect of BLM18H Series
[Testing Circuit]
74HCU04
74AC04
Measured radiation at 3m distance
74HC00
2
BLM
10MHz
Type of Filter
70
60
Level [dBµV/m]
50
40
30
20
10
300
400
EMI Suppression Effect
Description
Initial
(No filter)
500
600
700
800
Frequency [MHz]
900
1000
70
60
Level [dBµV/m]
50
Initial
40
30
20
10
300
400
500
600
700
800
Frequency [MHz]
900
1000
Current BLM are effective in suppressing
noise in the range between 300MHz and
700MHz.
Conventional Type
BLM18AG102SN1
(1000Ω at 100MHz)
70
60
Level [dBµV/m]
50
Initial
40
BLM18AG102SN1
30
20
10
300
400
500
600
700
800
Frequency [MHz]
900
1000
In addition to the effectiveness of current
BLM, BLM18HG suppresses noise in the
range beyond 700MHz.
for GHz Noize Suppression
BLM18HG102SN1
(1000Ω at 100MHz)
Comparison between BLM18HG102SN1 and
BLM18AG102SN1 (CURRENT ITEM)
Impedance [Ω]
2000
1500
BLM18HG102SN1
BLM18AG102SN1
1000
500
0
1
10
100
1000
2000
Frequency [MHz]
59
Embedded System
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