-8-
-9-
AB2.8X4.5DY 4.0±0.2 5.7±0.3 0.9min PBTBlack 10,000
AB3X2X3DY 4.0±0.2 4.2±0.3 0.9min PBTBlack 10,000
AB3X2X4.5DY 4.0±0.2 5.7±0.3 1.3min PBTGray 10,000
AB4X2X4.5DY 5.0±0.2 5.7±0.3 2.7min PBTBlack 5,000
AB4X2X6DY 5.0±0.2 7.2±0.3 3.6min PBTBlack 5,000
AMOBEADS 
2．NoiseSuppressionDevicesAMOBEADS
2．NoiseSuppressionDevicesAMOBEADS
B[T]
40 80
0
0.4
0.6
-0.6
-0.4
-0.2
0.2
-80 -40
Amorphous
Ferrite
H[A/m]
B-HCurve（typical）
AB3X2X3W 4.0 1.5 4.5 3.0 2.0 3.0 0.9 3.0
AB3X2X4.5W 4.0 1.5 6.0 3.0 2.0 4.5 1.3 5.0
AB3X2X6W 4.0 1.5 7.5 3.0 2.0 6.0 1.8 7.0
AB4X2X4.5W 5.0 1.5 6.0 4.0 2.0 4.5 2.7 9.0 
AB4X2X6W 5.0 1.5 7.5 4.0 2.0 6.0 3.6 12.0
AB4X2X8W 5.0 1.5 9.5 4.0 2.0 8.0 4.8 16.0
 FinishedDimensions[mm] CoreSize[mm]＊1  TotalFlux
＊
2 ALvalue
＊
3
O.D.max
I.D.min H.T.max
O.D.
I.D.

H.T. φc[μWb]min L[μH]min 
W
L
H
AMOBEADS withlead
AB／LBSeries
AB／LBSeries
ExampleforNoiseSuppressingEffect(ChopperConverter)
With an excellent saturable characteristic, "AMOBEADS " suppress the reverse recovery current of
thediodeanddecreasethenoisethatisoccurring.Whenthecurrentfordiodereversesandtriesto
go into the recovery condition, the "AMOBEADS " displays a large inductance and oppose the
generationoftherecoverycurrent.Inthisinstance,asoftrecoveryispossibleforcorematerialwitha
smallercoerciveforce.
WithoutCountermeasure WithAMOBEADS
(AB4×2×8W)
OutputNoise
DiodeCurrent
１A/div
2,000
An amorphous noise suppression device is unique and completely different from conventional noise
filters.Conventionalnoisepreventionproductsfocusonsomehowminimizingthenoiseafterit'sbeen
created,bytypicallytryingtoabsorbthenoise,andsotheireffectivenessinnoisereductionisdirectly
influencedbyfrequencyofthecircuit.Amorphousnoisesuppressingdevices,ontheotherhand,focus
onthesourceofthenoiseandworktopreventorminimizethenoisebeforeithasachancetodevelop.
The source of the electronic circuit noise is the rapid change of current or voltage, and the
effectivenessoftheamorphouscoresineliminatingthisnoiseisindependentoffrequency.
Anamorphousnoisesuppressiondeviceisaproductthattakesfulladvantageoftheuniquemagnetic
characteristicsofthecobaltbasedamorphousalloy.ToshibaMaterialsofferstwonoisesuppression
devices, "AMOBEADS " and "SPIKE KILLERS ". AMOBEADS " deliver excellent noise suppression
resultsandareconvenienttousebysimplybeingslippedovertheleadsofthesemiconductordevice.
"AMOBEADS"arealsoavailablewithaleadthruandinasurfacemountconfiguration."SPIKEKILLERS",which
are larger in size than "AMOBEADS ", most often are wire wound and are effective in eliminating or
minimizinghighernoiselevels.
Packing
Unit
[pcs/box]
Insulating
Cover
（100kHz,RT）
StandardSpecifications
☆"AMOBEADS "samplekitsareavailable.Pleaseasksalesdepartment.
☆"AMOBEADS "and"SPIKEKILLER ":RegisteredtrademarksofTOSHIBAMATERIALSCo.,Ltd.
☆"AMOBEADS "and"SPIKEKILLER ":ResisteredinU.S.A.,France,Germany,U.K.,Japan.
3.3
2.4
14.7
AB4X2X6SM
AB3X2X3SM
2.0
2.4
9.4
BasicSnubberCircuitDiagram
NoiseSuppressionDevice
RCSnubber MagneticSnubber
TypeNo.
PBTcase
Blue
SMDTypeAMOBEADS 
AB3X2X3SM 5.0±0.3 5.0±0.3 4.0±0.3 (1.8×0.35) （6.0） 0.9min 3.0 2,000
AB4X2X6SM 6.0±0.3 8.0±0.3 5.0±0.3 (1.8×0.52) （9.0） 3.6min 12.0 1,000
TypeNo.
＊4 ＊2 ＊3
[A] φc[μWb] L[μH]
Io TotalFlux ALvalue
LCPcase
Black
Lead
FinishedDimensions[mm]
width length height
widthxthickness
Insulating
Cover
Packing
Unit
[pcs/reel]
＊1ReferenceValue＊2MinimumGuaranteeonMeasuringCondition:50kHz、80A/m(sinewave),R.T.
＊3MeasuringCondition：50kHz,1V,1turn,R.T.
＊4TypicalValue,usingacrosssectionoflead
＊5MeasuringCondition：100kHz,80A/m（sinewave),R.T.＊6Tolerance±0.2［mm］
＊7ConvertedfromInductanceValueL
1
at1kHz、100mA(sinewave)、R.T.
  φｃ(μWb)＝0.282xL
1
(μＨ)
FinishedDimensions[mm]
TotalFlux*7
O.D. H.T. φc[μWb]
※Innerdiametercanpassthrougha1.2Ｘ0.7mmlead.
Insulating
Cover
PackingUnit
[
pcs
/bag］
TypeNo.
Current
Totalflux
ALValue
[A] φc[μWb] L[μH]
LB4X2X8F 16.0max 4.2±0.5 14.0±1.0 φ1.25±0.1
LB4X2X8U 20.0max 4.0±0.5 5.0±1.0 φ1.25±0.1
*4 *2 *3
1,000
FinishedDimensions[mm]
[pcs/box]
4.8
 min 16.0
min
（8.0）
TypeNo.
Insulating
Cover
PBTcase
Black
RecommendedLandPattern(mm)
Radialtaping
（Recommendforbigdemand,10,000pcs/lot)
D0
P
P0
ａ
ｄ
B
D
E
F
LB4X2X8U
     Current＊4 TotalFlux＊7
     I[A] φc[μWb]
3,000
LB2.8X4.5U 12.7 12.7 φ4.0 9.0max φ0.8 (5) 0.9min
Packing
Unit
B
D
E
F
LB4X2X8F
WseriesDYsereis
DYseries(lowprice)
Wseries
Bulktype
CR AB
RoHS
compliantproducts
RoHS
compliantproducts
B D E F
TypeNo.
[pcs/box]
Packing
Unit
P[mm] Po[mm] Do[mm] a[mm] d[mm]
-8-
-9-
AB2.8X4.5DY 4.0±0.2 5.7±0.3 0.9min PBTBlack 10,000
AB3X2X3DY 4.0±0.2 4.2±0.3 0.9min PBTBlack 10,000
AB3X2X4.5DY 4.0±0.2 5.7±0.3 1.3min PBTGray 10,000
AB4X2X4.5DY 5.0±0.2 5.7±0.3 2.7min PBTBlack 5,000
AB4X2X6DY 5.0±0.2 7.2±0.3 3.6min PBTBlack 5,000
AMOBEADS 
2．NoiseSuppressionDevicesAMOBEADS
2．NoiseSuppressionDevicesAMOBEADS
B[T]
40 80
0
0.4
0.6
-0.6
-0.4
-0.2
0.2
-80 -40
Amorphous
Ferrite
H[A/m]
B-HCurve（typical）
AB3X2X3W 4.0 1.5 4.5 3.0 2.0 3.0 0.9 3.0
AB3X2X4.5W 4.0 1.5 6.0 3.0 2.0 4.5 1.3 5.0
AB3X2X6W 4.0 1.5 7.5 3.0 2.0 6.0 1.8 7.0
AB4X2X4.5W 5.0 1.5 6.0 4.0 2.0 4.5 2.7 9.0 
AB4X2X6W 5.0 1.5 7.5 4.0 2.0 6.0 3.6 12.0
AB4X2X8W 5.0 1.5 9.5 4.0 2.0 8.0 4.8 16.0
 FinishedDimensions[mm] CoreSize[mm]＊1  TotalFlux
＊
2 ALvalue
＊
3
O.D.max
I.D.min H.T.max
O.D.
I.D.

H.T. φc[μWb]min L[μH]min 
W
L
H
AMOBEADS withlead
AB／LBSeries
AB／LBSeries
ExampleforNoiseSuppressingEffect(ChopperConverter)
With an excellent saturable characteristic, "AMOBEADS " suppress the reverse recovery current of
thediodeanddecreasethenoisethatisoccurring.Whenthecurrentfordiodereversesandtriesto
go into the recovery condition, the "AMOBEADS " displays a large inductance and oppose the
generationoftherecoverycurrent.Inthisinstance,asoftrecoveryispossibleforcorematerialwitha
smallercoerciveforce.
WithoutCountermeasure WithAMOBEADS
(AB4×2×8W)
OutputNoise
DiodeCurrent
１A/div
2,000
An amorphous noise suppression device is unique and completely different from conventional noise
filters.Conventionalnoisepreventionproductsfocusonsomehowminimizingthenoiseafterit'sbeen
created,bytypicallytryingtoabsorbthenoise,andsotheireffectivenessinnoisereductionisdirectly
influencedbyfrequencyofthecircuit.Amorphousnoisesuppressingdevices,ontheotherhand,focus
onthesourceofthenoiseandworktopreventorminimizethenoisebeforeithasachancetodevelop.
The source of the electronic circuit noise is the rapid change of current or voltage, and the
effectivenessoftheamorphouscoresineliminatingthisnoiseisindependentoffrequency.
Anamorphousnoisesuppressiondeviceisaproductthattakesfulladvantageoftheuniquemagnetic
characteristicsofthecobaltbasedamorphousalloy.ToshibaMaterialsofferstwonoisesuppression
devices, "AMOBEADS " and "SPIKE KILLERS ". AMOBEADS " deliver excellent noise suppression
resultsandareconvenienttousebysimplybeingslippedovertheleadsofthesemiconductordevice.
"AMOBEADS"arealsoavailablewithaleadthruandinasurfacemountconfiguration."SPIKEKILLERS",which
are larger in size than "AMOBEADS ", most often are wire wound and are effective in eliminating or
minimizinghighernoiselevels.
Packing
Unit
[pcs/box]
Insulating
Cover
（100kHz,RT）
StandardSpecifications
☆"AMOBEADS "samplekitsareavailable.Pleaseasksalesdepartment.
☆"AMOBEADS "and"SPIKEKILLER ":RegisteredtrademarksofTOSHIBAMATERIALSCo.,Ltd.
☆"AMOBEADS "and"SPIKEKILLER ":ResisteredinU.S.A.,France,Germany,U.K.,Japan.
3.3
2.4
14.7
AB4X2X6SM
AB3X2X3SM
2.0
2.4
9.4
BasicSnubberCircuitDiagram
NoiseSuppressionDevice
RCSnubber MagneticSnubber
TypeNo.
PBTcase
Blue
SMDTypeAMOBEADS 
AB3X2X3SM 5.0±0.3 5.0±0.3 4.0±0.3 (1.8×0.35) （6.0） 0.9min 3.0 2,000
AB4X2X6SM 6.0±0.3 8.0±0.3 5.0±0.3 (1.8×0.52) （9.0） 3.6min 12.0 1,000
TypeNo.
＊4 ＊2 ＊3
[A] φc[μWb] L[μH]
Io TotalFlux ALvalue
LCPcase
Black
Lead
FinishedDimensions[mm]
width length height
widthxthickness
Insulating
Cover
Packing
Unit
[pcs/reel]
＊1ReferenceValue＊2MinimumGuaranteeonMeasuringCondition:50kHz、80A/m(sinewave),R.T.
＊3MeasuringCondition：50kHz,1V,1turn,R.T.
＊4TypicalValue,usingacrosssectionoflead
＊5MeasuringCondition：100kHz,80A/m（sinewave),R.T.＊6Tolerance±0.2［mm］
＊7ConvertedfromInductanceValueL
1
at1kHz、100mA(sinewave)、R.T.
  φｃ(μWb)＝0.282xL
1
(μＨ)
FinishedDimensions[mm]
TotalFlux*7
O.D. H.T. φc[μWb]
※Innerdiametercanpassthrougha1.2Ｘ0.7mmlead.
Insulating
Cover
PackingUnit
[
pcs
/bag］
TypeNo.
Current
Totalflux
ALValue
[A] φc[μWb] L[μH]
LB4X2X8F 16.0max 4.2±0.5 14.0±1.0 φ1.25±0.1
LB4X2X8U 20.0max 4.0±0.5 5.0±1.0 φ1.25±0.1
*4 *2 *3
1,000
FinishedDimensions[mm]
[pcs/box]
4.8
 min 16.0
min
（8.0）
TypeNo.
Insulating
Cover
PBTcase
Black
RecommendedLandPattern(mm)
Radialtaping
（Recommendforbigdemand,10,000pcs/lot)
D0
P
P0
ａ
ｄ
B
D
E
F
LB4X2X8U
     Current＊4 TotalFlux＊7
     I[A] φc[μWb]
3,000
LB2.8X4.5U 12.7 12.7 φ4.0 9.0max φ0.8 (5) 0.9min
Packing
Unit
B
D
E
F
LB4X2X8F
WseriesDYsereis
DYseries(lowprice)
Wseries
Bulktype
CR AB
RoHS
compliantproducts
RoHS
compliantproducts
B D E F
TypeNo.
[pcs/box]
Packing
Unit
P[mm] Po[mm] Do[mm] a[mm] d[mm]
-10-
-11-
ChopperConverter ControlCircuitforMotor
MotorDrivingCircuit
ForwardConverter
AB
AB
M
Push-pullConverter
EffectsofNoiseSuppressionbyAMOBEADS
EffectsofNoiseSuppressionbyAMOBEADS
OutputNoiseReduction
SpikeVoltageSuppression
PrimarySurgeVoltage
OutputNoise
VN
20mv/div
OutputNoise
VN
50mv/div
DiodeVoltage
VD
10V/div
MOS-FET
Drain-Source
Voltage
VDS
200V/div
DiodeCurrent
ID
5A/div
ActualBHCurve
OutputNoise
WithoutCountermeasure
BHcharacteristicsofFerrite
B
H
AB
AB
AB
AB
M
RCSnubber+FerriteBeads AMOBEADS"AB4×2×4.5Ｗ"
AMOBEADS"AB4×2×4.5Ｗ"
FerriteBeads4×2×4 AMOBEADS"AB4×2×4.5Ｗ"
Frequency：500kHz
OutputVoltage-Current
：5Ｖ-20Ａ
CorelossCharacteristic[AMOBEADS]
ApplicationofAmorphousNoiseSuppressionDevices
1
10
100
1000
10000
0.01 0.1 1
ΔB¦[T]
Pfe[kW/m3］
50kH z
100kH z
200kH z
300kH z
500kH z
Characteristics(Typicalvalue)
Temperature[℃]
0 20 40 60 80 100 120
0.
50
100
φ(t)/φ(25℃)
1k 10k 100k 1M
1
0.1
10
100
ALvalue［μＨ]
AB3×2×6W
AB3×2×4.5W
AB2.8×4.5DY
AB3×2×3W
AB4×2×6W
AB4×2×4.5W
AB4×2×8W
FrequencyCharacteristicsofInductance
Frequencyf[Hz]
Typicalvalue
R.T.
SineWave
TypicalValue
R.T.
Spikevoltagecan bereduced
and ringing phenomena can
also be prevented by
AMOBEADS. Also Schottky
barrier diode (SBD) can be
protectedfromovervoltage.
ExamplesofAppliedCircuitsandtheirCharacteristics
ExamplesofAppliedCircuitsandtheirCharacteristics
FlybackConverter
Flux(φ)DeclineRatiovs.Temperature
Frequency：150kHz
OutputVoltage-Current
：15Ｖ-10Ａ
Frequency：250kHz
OutputVoltage-Current
：5Ｖ-15Ａ
BHcharacteristicsofAmobeads
Whentheferriteisreplacedby
AMOBEADSatthesecondary
output diode (FRD) of the
forward converter circuit, the
output noise can be tremen-
dously reduced, not only the
noise peak level but also the
amplituderange.
Whentheferriteisreplacedby
AMOBEADSatthesecondary
output diode (SBD) of the
forward converter circuit, the
output noise and harmful
influencetotheprimarystage
can be reduced. These
effects are based on the
inclination of the actual BH
curves between amorphous
andferritematerials.
AB
AB
AB
AB
AB
AB
-10-
-11-
ChopperConverter ControlCircuitforMotor
MotorDrivingCircuit
ForwardConverter
AB
AB
M
Push-pullConverter
EffectsofNoiseSuppressionbyAMOBEADS
EffectsofNoiseSuppressionbyAMOBEADS
OutputNoiseReduction
SpikeVoltageSuppression
PrimarySurgeVoltage
OutputNoise
VN
20mv/div
OutputNoise
VN
50mv/div
DiodeVoltage
VD
10V/div
MOS-FET
Drain-Source
Voltage
VDS
200V/div
DiodeCurrent
ID
5A/div
ActualBHCurve
OutputNoise
WithoutCountermeasure
BHcharacteristicsofFerrite
B
H
AB
AB
AB
AB
M
RCSnubber+FerriteBeads AMOBEADS"AB4×2×4.5Ｗ"
AMOBEADS"AB4×2×4.5Ｗ"
FerriteBeads4×2×4 AMOBEADS"AB4×2×4.5Ｗ"
Frequency：500kHz
OutputVoltage-Current
：5Ｖ-20Ａ
CorelossCharacteristic[AMOBEADS]
ApplicationofAmorphousNoiseSuppressionDevices
1
10
100
1000
10000
0.01 0.1 1
ΔB¦[T]
Pfe[kW/m3］
50kH z
100kH z
200kH z
300kH z
500kH z
Characteristics(Typicalvalue)
Temperature[℃]
0 20 40 60 80 100 120
0.
50
100
φ(t)/φ(25℃)
1k 10k 100k 1M
1
0.1
10
100
ALvalue［μＨ]
AB3×2×6W
AB3×2×4.5W
AB2.8×4.5DY
AB3×2×3W
AB4×2×6W
AB4×2×4.5W
AB4×2×8W
FrequencyCharacteristicsofInductance
Frequencyf[Hz]
Typicalvalue
R.T.
SineWave
TypicalValue
R.T.
Spikevoltagecan bereduced
and ringing phenomena can
also be prevented by
AMOBEADS. Also Schottky
barrier diode (SBD) can be
protectedfromovervoltage.
ExamplesofAppliedCircuitsandtheirCharacteristics
ExamplesofAppliedCircuitsandtheirCharacteristics
FlybackConverter
Flux(φ)DeclineRatiovs.Temperature
Frequency：150kHz
OutputVoltage-Current
：15Ｖ-10Ａ
Frequency：250kHz
OutputVoltage-Current
：5Ｖ-15Ａ
BHcharacteristicsofAmobeads
Whentheferriteisreplacedby
AMOBEADSatthesecondary
output diode (FRD) of the
forward converter circuit, the
output noise can be tremen-
dously reduced, not only the
noise peak level but also the
amplituderange.
Whentheferriteisreplacedby
AMOBEADSatthesecondary
output diode (SBD) of the
forward converter circuit, the
output noise and harmful
influencetotheprimarystage
can be reduced. These
effects are based on the
inclination of the actual BH
curves between amorphous
andferritematerials.
AB
AB
AB
AB
AB
AB