EMI Filters
KNF Series
Features
Applications
• Distributed constant type LC filter.
Prevents ringing caused by circuit
impedance.
Suitable for high speed digital circuits and
video signal lines.
• Stable noise attenuation over wide
frequency ranges.
• Low profile (T=0.95mm max.) suitable for
miniature electronic equipments.
• First class auto-placement
• PCs, Laser Printers, Cellular Phone, Clock
Data Lines for LCD Display
• High Speed Video Signal Circuits and
Interface Circuits
• High Speed Digital Circuits
• Anti-Noise Solution
Achieves Effective Noise Suppression in
Noisy High Speed Circuits without Signal
Waveform Distortion
Dimensions Specifications(Unit : mm)
Frequency Characteristics
Equivalent Circuit
KNF21 Series
KNF21
L2.00.2
W1.250.2
T0.80.15
G0.40.3
KNF21025
KNF21050
KNF21100
KNF21200
KNF21400
Cut off
Freq.
(MHz)
Capacitance
(+50/-20%)
(pF)
20dB Attenuation
(Typical)
Rated
current(mA)
Rated
voltage(VDC)
25MHz 235pF 200– 600MHz
50MHz 130pF 350– 850MHz
100MHz 65pF 450– 950MHz 150mA 25VDC
200MHz 33pF 700–1200MHz
400MHz 17pF 900–1400MHz
IN OUT
GND
Frequency(MHz)
How to Order
KNF 21 050 - W 3
①Series
②Size EIA (EIAJ)
21 :0805 (2012)
③Frequency
④Taping Direction (See Fig 1)
W: Standard
⑤Quantity per Reel
① ② ③ ④ ⑤
025 25MHz 200 200MHz
050 50MHz 400 400MHz
100 100MHz
33000pcs.
Part Number
Cut off Frequency at Attenuation typical 3dB, max. 6dB
Operating Temperature: -25 to 85(°C)
-50
-40
-30
-20
-10
0
10
1 10 100 1000 10000
KNF21400
KNF21200
KNF21100
KNF21050
KNF21025
RoHS Compliant
Input Direction Mark
L
W
T
G
IN OUT
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EMI Filters
KNF Series
<Impedance Matching Free>
•
Stable attenuation against impedance change
• Good impedance matching without ringing
on distortion even at the time of IC ON/OFF
and pattern layout change
• Wide attenuation up to high frequency range
without distortion
<No Ringing>
Excellent Impedance Matching
Recommended Land Pattern (Unit : mm)
(Unit : mm)
Packaging Specification (Fig.1)
• Taping (3,000/reel)
Test Circuit
Wide Attenuation Bandwidth
Test circuit
Output Waveform (Clock frequency 25MHz)
Test point
LVC04
filter
LVC74
LC filter KNF21100R
1M
300
Test point
filterLVC74
50mm
25MHz 25
120
100
80
60
40
925825725625525
Frequency(MHz)
Spectrum att.(dBuV)
425325225125 25
120
100
80
60
40
925825725625525
Frequency(MHz)
Spectrum att.(dBuV)
425325225125
Original
Filter passed
Original
Filter passed
W(Standard)
Direction of Feed
Taping Direction(W)
4.0
8.0
T W R C P Q S D U
KNF21
3.20 2.30 1.00 1.20 0.80 0.40 0.60 0.3-0.4 2.00
KNF21100 LC Filter (T-Type)
KNF series
Output waveform
LC filter
Output waveform
No filter
Output waveform
P
C
T
S
Q
Through Hole
D
Resist
Resist
R
W
Conductor
U
R
25MHz
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Features
• 0805 Size. Rated current up to 2A.
• Effective for filtering noise on power (Vcc)
lines.
Applications
• PCs, Laser Printers, Cellular Phone,
Power/Signal Lines for LCD Display, Office
Equipments
• AV Power Supply/Signal Line, TV, VCR, etc.
• High Current Signal Lines
Dimensions (Unit : mm)
How to Order
KNH 21 104 - 3 AA
①Series
②Size EIA (EIAJ)
21: 0805 (2012)
③Capacitance Value
④Quantity per Reel
⑤Code (AA : STD)
① ② ③ ④ ⑤
104 100nF 101 100pF
473 47nF 470 47pF
471 470pF 220 22pF
221 220pF
33000pcs.
KNH21104
KNH21473
KNH21471
KNH21221
KNH21101
KNH21470
KNH21220
100,000 2.0 25 0.02
47,000 2.0 50 0.02
470 1.0 50 0.08
220 1.0 50 0.08
100 1.0 50 0.08
47 1.0 50 0.08
22 1.0 50 0.08
Specifications
Direct-current
resistance
()
Rated Voltage
(VDC)
Rated Current
(A)
Capacitance
Value(pF)
(+50/-20%)
Type
Operating Temperature: -25 to 85(°C)
Attenuation Characteristics
Attenuation(dB)
Frequency(MHz)
-50
-60
-70
-40
-30
-20
-10
0
10
1 10 100 1000 10000
KNH21104
KNH21473
KNH21220
KNH21470
KNH21101
KNH21221
KNH21471
<Electrical Characteristics>
•
Wide attenuation range including surrounding
circuit.
Test Circuit
Test point
VDD(3.3V)
LVC74
25MHz
filter
Attenuation Effect of Power Supply Noise
KNH series LC filter
25
60
55
50
45
40
35
30 925825725625525
FREQ(MHz)
Spectrum attenuation(dBuV)
425325225125
Original
Filter passed
Original
Filter passed
25
60
55
50
45
40
35
30 925825725625525
FREQ(MHz)
Spectrum attenuation(dBuV)
425325225125
(Unit : mm)
Packaging specifications
• Taping (3000/reel)
4.0
8.0
Recommended Land Pattern
(Unit : mm)
0.80
1.20
3.20
0.40
0.60
Through Hole
0.3–0.4
Resist
Resist
Conductor
1.00
2.30
2.00
Pb Free
RoHS Compliant
KNH21
2.00.2
1.250.2
0.850.15
0.400.30
L
W
T
G
L
W
T
G
IN/OUT IN/OUT
EMI Filters
KNH Series
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