BLM18BA121SH1D Murata, BLM18BA121SH1D Datasheet - Page 43

• Manufacturer Part Number: BLM18BA121SH1D
• Description: EMI/RFI Suppressors & Ferrites 0603 120ohms HiSpeed Signal Line Tape
• Manufacturer: Murata
• Series: BLM Br

Specifications of BLM18BA121SH1D

• Shielding: Unshielded
• Test Frequency: 100 MHz
• Product: Chip Ferrite Beads
• Impedance: 120 Ohms
• Tolerance: 25 %
• Maximum Dc Current: 200 mAmps
• Maximum Dc Resistance: 0.9 Ohms
• Operating Temperature Range: - 55 C to + 125 C
• Package / Case: 0603 (1608 metric)
• Termination Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

!Note
4. Capacitive Noise Suppression
5. High frequency Capacitor Characteristics Used
6. Inductive Noise Suppression
!Note
42
Noise Suppression Principles by DC EMIFILr
for EMI Suppression Filters
When a capacitor is connected (bypass capacitor) to
ground from a noisy signal line or power line, the circuit
impedance decreases as the frequency increases. Since
noise is a high frequency phenomenon, it flows to ground
if a capacitor has been connected to ground, thereby
making it possible to eliminate noise. (See Fig.)
EMI suppression filters employing a capacitor in this way
are used to eliminate this type of noise.
Even general-purpose capacitors can be used for noise
suppression. However, since noise has an extremely high
frequency range, general-purpose capacitors may not
function as effective bypass capacitors, due to the large
residual inductance built into the capacitor.
All the capacitors used in Murata's EMI suppression
filters employ a three terminal structure or thru-type
structure, which functions effectively even at high
frequencies, thereby minimizing the influence of residual
inductance. Consequently, an effective filter circuit can be
formed even at frequencies exceeding 1GHz.
(Refer to Fig.)
When an inductor is inserted in series in a noise
producing circuit (See Fig.), its impedance increases with
frequency. In this configuration it is possible to attenuate
and eliminate noise components (high frequency
components). The Murata EMI suppression filter
functions in this way.
Continued from the preceding page.
• Please read rating and !CAUTION (for storage, operating, rating, soldering, mounting and handling) in this catalog to prevent smoking and/or burning, etc.
• This catalog has only typical specifications because there is no space for detailed specifications. Therefore, please approve our product specifications or transact the approval sheet for product specifications before ordering.
Please read rating and !CAUTION (for storage, operating, rating, soldering, mounting and handling) in this PDF catalog to prevent smoking and/or burning, etc.
This catalog has only typical specifications. Therefore, you are requested to approve our product specifications or to transact the approval sheet for product specifications before ordering.
[Capacitive Noise Suppression]
[Equivalent circuit of general-purpose capacitor and
(a) Equivalent circuit of capacitors which is concerning ESL effect.
(b) Improvement of Insertion Loss Characteristics
[Inductive Noise Suppression]
Noise+Signal/DC Power
Noise+Signal/DC Power
three terminal capacitor in the high frequency area
and comparison of insertion loss]
10
20
30
40
50
60
70
80
0
1
10
Three terminal capacitor
Two terminal capacitor
Noise
C=22,000pF
C=22,000pF
Frequency (MHz)
100
Z =
Continued on the following page.
Z =
f : Frequency
c : Capacitance Value
2 fL
Noise
2 fc
f : Frequency
L : Capacitance Value
1
1000
(50 ohm - 50 ohm)
Signal/DC Power
Signal/DC Power
C50E.pdf 05.1.28
10000