− 1 −
アモルファス磁性部品
Amorphous Magnetic Parts
Amorphous Magnetic Parts
http://www.toshiba-tmat.co.jp/ 2K1412
Amorphous Magnetic Parts
English
− 2 −
Amorphous Magnetic Materials and their Applications
Amorphous Magnetic Materials and their Applications
Amorphous alloy is a general term for a metal with a non-crystalline structure of atoms.
Regular alloys have a uniformly formed metallic crystalline structure, but for amorphous alloys,
the atoms are distributed randomly. As a result of this random atomic distribution, the
magnetic properties of amorphous alloys are anisotropic. Also, in addition to an increase of
electrical resistivity, thin ribbons are made so that the eddy current losses will be small and
the magnetic characteristics will be significantly improved.
At Toshiba Materials, we manufacture a Cobalt based amorphous alloy by the liquid rapid
cooling method. This method of rapid cooling, at a rate of about 1 million degrees per second,
prevents the metal from solidifying in an amorphous structure rather than in its normal
ordered crystalline structure.
Amorphous Alloy
Regular Alloy
(Crystalline Structure)
Models of Atomic Arrangement
Amorphous Ribbon
There is a magnetic metal material with very unique characteristics that does not have a
crystalline structure. At Toshiba Materials, we focused on the excellent magnetic
characteristic of this amorphous magnetic alloy and started research and development years
ago, anticipating future applications and need for such a product. This Amorphous alloy was
called "alloy of dreams" at the time when we started our research but in recent years, it has
and is finding application in electrical products (desk top computer, copying machine, printer
etc.) Amorphous magnetic parts make it possible to reduce energy consumption, and minimize
electronic circuit noise for electrical products with a product considered environmentally
friendly (RoHS).
Amorphous Alloy
(Non Crystalline Structure)
Index
1．Noise Suppressor Devices AMOBEADSTM
Noise Suppression Devices 4
AB/LB series Standard Specifications 5
Examples of Applied Circuits and their Characteristics
6
Effects of Noise Suppression by AMOBEADSTM 7
2．Noise Suppressor Devices SPIKE KILLERSTM
SPIKE KILLERSTM 8
Wired SPIKE KILLERSTM and AMOBEADSTM 8
Examples of Applied Circuits and Effects of Noise Suppression
9
3．Saturable Cores for Mag-Amps
Saturable Cores for Mag-Amps 10
MT/MS Series Standard Specifications 11
Merits of Mag-Amp Method 12
Full Mag-Amp Metod 12
Examples of Circuit and Characteristics 13
4．
High Magnetic Permeability Cores for Pulse Transformer
High Magnetic Permeability Cores 14
Characteristics 14
FS Series Standard Specifications 15
Applications 15
～Instructions～
How to Select the Proper Size "AmobeadsTM " 16
Principle of the Noise Suppressing Device 17
Mag-Amp Operating Principle 18
Mag-Amp Design (Forward Converter) 19
Examples of the Design 20
Evaluation of the Mag-Amp Circuit Unit 21
Glossary of Amorphous Magnetic Parts 22
Notices on Handle 23
Maintenance and Discontinue List 23
− 3 −
Amorphous Magnetic Materials and their Applications
Amorphous Magnetic Materials and their Applications
Amorphous alloy is a general term for a metal with a non-crystalline structure of atoms.
Regular alloys have a uniformly formed metallic crystalline structure, but for amorphous alloys,
the atoms are distributed randomly. As a result of this random atomic distribution, the
magnetic properties of amorphous alloys are anisotropic. Also, in addition to an increase of
electrical resistivity, thin ribbons are made so that the eddy current losses will be small and
the magnetic characteristics will be significantly improved.
At Toshiba Materials, we manufacture a Cobalt based amorphous alloy by the liquid rapid
cooling method. This method of rapid cooling, at a rate of about 1 million degrees per second,
prevents the metal from solidifying in an amorphous structure rather than in its normal
ordered crystalline structure.
Amorphous Alloy
Regular Alloy
(Crystalline Structure)
Models of Atomic Arrangement
Amorphous Ribbon
There is a magnetic metal material with very unique characteristics that does not have a
crystalline structure. At Toshiba Materials, we focused on the excellent magnetic
characteristic of this amorphous magnetic alloy and started research and development years
ago, anticipating future applications and need for such a product. This Amorphous alloy was
called "alloy of dreams" at the time when we started our research but in recent years, it has
and is finding application in electrical products (desk top computer, copying machine, printer
etc.) Amorphous magnetic parts make it possible to reduce energy consumption, and minimize
electronic circuit noise for electrical products with a product considered environmentally
friendly (RoHS).
Amorphous Alloy
(Non Crystalline Structure)
Index
1．Noise Suppressor Devices AMOBEADSTM
Noise Suppression Devices 4
AB/LB series Standard Specifications 5
Examples of Applied Circuits and their Characteristics
6
Effects of Noise Suppression by AMOBEADSTM 7
2．Noise Suppressor Devices SPIKE KILLERSTM
SPIKE KILLERSTM 8
Wired SPIKE KILLERSTM and AMOBEADSTM 8
Examples of Applied Circuits and Effects of Noise Suppression
9
3．Saturable Cores for Mag-Amps
Saturable Cores for Mag-Amps 10
MT/MS Series Standard Specifications 11
Merits of Mag-Amp Method 12
Full Mag-Amp Metod 12
Examples of Circuit and Characteristics 13
4．
High Magnetic Permeability Cores for Pulse Transformer
High Magnetic Permeability Cores 14
Characteristics 14
FS Series Standard Specifications 15
Applications 15
～Instructions～
How to Select the Proper Size "AmobeadsTM " 16
Principle of the Noise Suppressing Device 17
Mag-Amp Operating Principle 18
Mag-Amp Design (Forward Converter) 19
Examples of the Design 20
Evaluation of the Mag-Amp Circuit Unit 21
Glossary of Amorphous Magnetic Parts 22
Notices on Handle 23
Maintenance and Discontinue List 23
− 4 −
- 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
AB4X2X6DY 5.0±0.2 7.2±0.3 3.6min PBT Black 5,000
AB5X4X3DY 5.95±0.2 4.2±0.3 0.45min PBT Black 5,000
AMOBEADSTM
1． Noise Suppression Devices AMOBEADSTM
1． Noise Suppression Devices AMOBEADSTM
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
AMOBEADSTM with lead
AB／LB Series
AB／LB Series
Example for Noise Suppressing Effect (Chopper Converter)
With an excellent saturable characteristic, "AMOBEADSTM " 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 "AMOBEADSTM " 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 AMOBEADSTM
(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, "AMOBEADSTM " and "SPIKE KILLERSTM ". AMOBEADSTM " deliver excellent noise suppression
results and are convenient to use by simply being slipped over the leads of the semiconductor device.
"AMOBEADSTM " are also available with a lead thru and in a surface mount configuration. "SPIKE KILLERSTM ",
which are larger in size than "AMOBEADSTM ", 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
☆"AMOBEADSTM " sample kits are available. Please ask sales department.
☆"AMOBEADSTM " and "SPIKE KILLERTM " : Registered trademarks of TOSHIBA MATERIALS Co., Ltd.
☆"AMOBEADSTM " and "SPIKE KILLERTM " : 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 AMOBEADSTM
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.
However, Inner diameter of AB5x4x3DY can pass through a 2.5x0.7 mm 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]
− 5 −
- 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
AB4X2X6DY 5.0+0.2/-0.3 7.2±0.3 3.6min PBT Black 5,000
AB5X4X3DY 5.95±0.2 4.2±0.3 0.45min PBT Black 5,000
AMOBEADSTM
1． Noise Suppression Devices AMOBEADSTM
1． Noise Suppression Devices AMOBEADSTM
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
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
AMOBEADSTM with lead
AB／LB Series
AB／LB Series
Example for Noise Suppressing Effect (Chopper Converter)
With an excellent saturable characteristic, "AMOBEADSTM " 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 "AMOBEADSTM " 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 AMOBEADSTM
(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, "AMOBEADSTM " and "SPIKE KILLERSTM ". AMOBEADSTM " deliver excellent noise suppression
results and are convenient to use by simply being slipped over the leads of the semiconductor device.
"AMOBEADSTM " are also available with a lead thru and in a surface mount configuration. "SPIKE KILLERSTM ",
which are larger in size than "AMOBEADSTM ", 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
☆"AMOBEADSTM " sample kits are available. Please ask sales department.
☆"AMOBEADSTM " and "SPIKE KILLERTM " : Registered trademarks of TOSHIBA MATERIALS Co., Ltd.
☆"AMOBEADSTM " and "SPIKE KILLERTM " : 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 AMOBEADSTM
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.
However, Inner diameter of AB5x4x3DY can pass through a 2.5x0.7 mm 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]
− 6 −
- 10 - - 11 -
Chopper Converter Control Circuit for Motor
Motor Driving Circuit
Forward Converter
AB
AB
M
Push-pull Converter
Effects of Noise Suppression by AMOBEADSTM
Effects of Noise Suppression by AMOBEADSTM
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 AMOBEADSTM "AB4×2×4.5Ｗ"
AMOBEADSTM "AB4×2×4.5Ｗ"
Ferrite Beads 4×2×4 AMOBEADSTM "AB4×2×4.5Ｗ"
Frequency：500kHz
Output Voltage - Current
：5Ｖ-20Ａ
Coreloss Characteristic [AMOBEADSTM ]
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 AMOBE-
ADS. 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
− 7 −
- 10 - - 11 -
Chopper Converter Control Circuit for Motor
Motor Driving Circuit
Forward Converter
AB
AB
M
Push-pull Converter
Effects of Noise Suppression by AMOBEADSTM
Effects of Noise Suppression by AMOBEADSTM
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 AMOBEADSTM "AB4×2×4.5Ｗ"
AMOBEADSTM "AB4×2×4.5Ｗ"
Ferrite Beads 4×2×4 AMOBEADSTM "AB4×2×4.5Ｗ"
Frequency：500kHz
Output Voltage - Current
：5Ｖ-20Ａ
Coreloss Characteristic [AMOBEADSTM ]
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 AMOBE-
ADS. 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
− 8 −
- 12 - - 13 -
JPN.P. No. 3190775
Toshiba Materials Co. Ltd.
USP No. 5745353 〃
Diode Clamp
（68ｋΩ、0.022μF）
CR Snubber
(10Ω、1500ｐF）
Wired AMOBEADSTM
AB44DY0307 applied
Vds
100V/div
Id
1A/div
Swirching
Waveform
Turn-on
Waveform
Output Voltage
Noise
Vds
100V/div
Id
0.5A/div
Vn
20mV/div
Example of Effects（Delaytor）
*1 Tolerance ±0.2［mm］ *2 Reference value
*3 Measuring condition：100kHz、80A/m (sine wave), R.T.
2 ．
Noise Suppression Devices SPIKE KILLERTM
2 ．
Noise Suppression Devices SPIKE KILLERTM
SS7X4X3W
9.1 3.3 4.8 7.5 4.5 3.0 3.38 18.8 3.15
SS10X7X4.5W 11.5 5.8 6.6 10.0 7.0 4.5 5.06 26.7 4.73
SS14X8X4.5W
15.8 6.8 6.6 14.0 8.0 4.5 10.1 34.6 9.46
22max 90min
*1
☆ "SPIKE KILLERTM " : Registered trademarks of TOSHIBA MATERIALS Co., Ltd.
☆ "SPIKE KILLERTM " : Resistered in U.S.A., France, Germany, U.K., Japan.
SPIKEK KILLERTM
*1： Typical Value, using a cross section of winding wire
*2：Total Flux of core × turn
Chopper Converter
Example of applied circuit and it’s characterisitic
Example Circuit：Self-Exiting Single Flyback(RCC)
Wired AMOBEADSTM delay the turn-on time of the MOSFET when they are inserted between the gate of
the MOSFET and drive winding on the primary side of the self-exiting single flyback (RCC). The wired
AMOBEADSTM reduce both noise, due to surge current and switching loss, by turning on the switching
element at the point when the voltage of the transformer becomes low, utilizing the the LC resonance
phenomenon induced by inductance L of the primary winding of the transformer and a snubber capacitor C.
Note : The diode clamp circuit has a tendency to increase the out put noise.
Power Supply Efficiency（Vin:DC140V, Vo:24V)
100%
90%
80%
70%
60%
50%
40%
0 0.5 1 1.5 2 2.5 3
Output Currrent［Ａ］
Eficiency［％］
CR Snubber
Wired AMOBEADSTM
Diode Clamp
Type of wire：1UEW
3max
soldered
A
15±5
B
SR：Wired AMOBEADSTM
L
RgCgQ1
R
C
+
SR
Current
*1
Wire Dia.
N
Flux*2
Dimensions[mm]
AB44DY0305 AB4x2x4.5DY 0.5 0.3 5 13.5 7 9
AB44DY0307 AB4x2x4.5DY 0.5 0.3 7 18.9 7 9
SS07S0309 SS7x4x3W 0.5 0.3 9 28.3 12 8
AB34DY0402 AB3x2x4.5DY 1.0 0.4 2 2.6 6 9
AB34DY0403 AB3x2x4.5DY 1.0 0.4 3 3.9 6 9
AB44DY0402 AB4x2x4.5DY 1.0 0.4 2 5.4 7 9
AB44DY0403 AB4x2x4.5DY 1.0 0.4 3 8.1 7 9
AB44DY0404 AB4x2x4.5DY 1.0 0.4 4 10.8 7 9
SS07S0507 SS7x4x3W 1.5 0.5 7 22.1 12 8
SS07S0510 SS7x4x3W 1.5 0.5 10 31.5 12 8
SS07S0515 SS7x4x3W 1.5 0.5 15 47.3 12 8
SS10S05105 SS10x7x4.5W 1.5 0.5 5 23.7 14 10
SS10S05107 SS10x7x4.5W 1.5 0.5 7 33.1 14 10
SS10S05110 SS10x7x4.5W 1.5 0.5 10 47.3 14 10
SS10S09110 SS10x7x4.5W 5 0.9 10 47.3 15 11
SS14S09108 SS14x8x4.5W 5 0.9 8 75.7 20 11
SS14S09205 SS14x8x4.5W 10 0.9x2 5 47.3 20 11
Input 20[V］
Output 12[V]／2[A]
Frequency 90kHz
Rectifier FRD
Detector Simple Loop Antenna
Testing Condition of Radiant Noise Measurment
RoHS
compliant products
RoHS
compliant products
Standard Specifications
＊
2
＊
2
＊
2
＊
3
＊
3
＊
3
Type No.
Type No. Core No.
PET case
Black
Finished Dimensions [mm]
Insulating
Cover
Core Size [mm]
Effective core
cross section
Ae[mm2] Lm [mm] φc[μWb]min Hc[A/m] Br/Bm[%]
Mean Flux
Path Length Total Flux
O.D. I.D. H.T O.D. I.D. H.T
Coercive
Force
Rectangular
Ratio
Wired SPIKE KILLERTM and AMOBEADSTM
[A] [φmm] [turn] [uWb] A
max
B
max
12 24 36 48 60 72 84 96 108 120
Frequency［MHz］
FM radio band
AMOBEADSTM
Without Countermeasure
[dB/div]
ＣＲ Snubber
Noise Radiation
Examples of Applied Circuits and Effects of Noise Suppression
Examples of Applied Circuits and Effects of Noise Suppression
− 9 −
- 12 - - 13 -
JPN.P. No. 3190775
Toshiba Materials Co. Ltd.
USP No. 5745353 〃
Diode Clamp
（68ｋΩ、0.022μF）
CR Snubber
(10Ω、1500ｐF）
Wired AMOBEADSTM
AB44DY0307 applied
Vds
100V/div
Id
1A/div
Swirching
Waveform
Turn-on
Waveform
Output Voltage
Noise
Vds
100V/div
Id
0.5A/div
Vn
20mV/div
Example of Effects（Delaytor）
*1 Tolerance ±0.2［mm］ *2 Reference value
*3 Measuring condition：100kHz、80A/m (sine wave), R.T.
2 ．
Noise Suppression Devices SPIKE KILLERTM
2 ．
Noise Suppression Devices SPIKE KILLERTM
SS7X4X3W
9.1 3.3 4.8 7.5 4.5 3.0 3.38 18.8 3.15
SS10X7X4.5W 11.5 5.8 6.6 10.0 7.0 4.5 5.06 26.7 4.73
SS14X8X4.5W
15.8 6.8 6.6 14.0 8.0 4.5 10.1 34.6 9.46
22max 90min
*1
☆ "SPIKE KILLERTM " : Registered trademarks of TOSHIBA MATERIALS Co., Ltd.
☆ "SPIKE KILLERTM " : Resistered in U.S.A., France, Germany, U.K., Japan.
SPIKEK KILLERTM
*1： Typical Value, using a cross section of winding wire
*2：Total Flux of core × turn
Chopper Converter
Example of applied circuit and it’s characterisitic
Example Circuit：Self-Exiting Single Flyback(RCC)
Wired AMOBEADSTM delay the turn-on time of the MOSFET when they are inserted between the gate of
the MOSFET and drive winding on the primary side of the self-exiting single flyback (RCC). The wired
AMOBEADSTM reduce both noise, due to surge current and switching loss, by turning on the switching
element at the point when the voltage of the transformer becomes low, utilizing the the LC resonance
phenomenon induced by inductance L of the primary winding of the transformer and a snubber capacitor C.
Note : The diode clamp circuit has a tendency to increase the out put noise.
Power Supply Efficiency（Vin:DC140V, Vo:24V)
100%
90%
80%
70%
60%
50%
40%
0 0.5 1 1.5 2 2.5 3
Output Currrent［Ａ］
Eficiency［％］
CR Snubber
Wired AMOBEADSTM
Diode Clamp
Type of wire：1UEW
3max
soldered
A
15±5
B
SR：Wired AMOBEADSTM
L
RgCgQ1
R
C
+
SR
Current
*1
Wire Dia.
N
Flux*2
Dimensions[mm]
AB44DY0305 AB4x2x4.5DY 0.5 0.3 5 13.5 7 9
AB44DY0307 AB4x2x4.5DY 0.5 0.3 7 18.9 7 9
SS07S0309 SS7x4x3W 0.5 0.3 9 28.3 12 8
AB34DY0402 AB3x2x4.5DY 1.0 0.4 2 2.6 6 9
AB34DY0403 AB3x2x4.5DY 1.0 0.4 3 3.9 6 9
AB44DY0402 AB4x2x4.5DY 1.0 0.4 2 5.4 7 9
AB44DY0403 AB4x2x4.5DY 1.0 0.4 3 8.1 7 9
AB44DY0404 AB4x2x4.5DY 1.0 0.4 4 10.8 7 9
SS07S0507 SS7x4x3W 1.5 0.5 7 22.1 12 8
SS07S0510 SS7x4x3W 1.5 0.5 10 31.5 12 8
SS07S0515 SS7x4x3W 1.5 0.5 15 47.3 12 8
SS10S05105 SS10x7x4.5W 1.5 0.5 5 23.7 14 10
SS10S05107 SS10x7x4.5W 1.5 0.5 7 33.1 14 10
SS10S05110 SS10x7x4.5W 1.5 0.5 10 47.3 14 10
SS10S09110 SS10x7x4.5W 5 0.9 10 47.3 15 11
SS14S09108 SS14x8x4.5W 5 0.9 8 75.7 20 11
SS14S09205 SS14x8x4.5W 10 0.9x2 5 47.3 20 11
Input 20[V］
Output 12[V]／2[A]
Frequency 90kHz
Rectifier FRD
Detector Simple Loop Antenna
Testing Condition of Radiant Noise Measurment
RoHS compliant products
RoHS compliant products
Standard Specifications
＊
2
＊
2
＊
2
＊
3
＊
3
＊
3
Type No.
Type No. Core No.
PET case
Black
Finished Dimensions [mm]
Insulating
Cover
Core Size [mm]
Effective core
cross section
Ae[mm2] Lm [mm] φc[μWb]min Hc[A/m] Br/Bm[%]
Mean Flux
Path Length Total Flux
O.D. I.D. H.T O.D. I.D. H.T
Coercive
Force
Rectangular
Ratio
Wired SPIKE KILLERTM and AMOBEADSTM
[A] [φmm] [turn] [uWb] A
max
B
max
12 24 36 48 60 72 84 96 108 120
Frequency［MHz］
FM radio band
AMOBEADSTM
Without Countermeasure
[dB/div]
ＣＲ Snubber
Noise Radiation
Examples of Applied Circuits and Effects of Noise Suppression
Examples of Applied Circuits and Effects of Noise Suppression
− 10 −
The Mag-amp method is one of several output voltage regulation methods used in switching power supplies.
A saturable core is used in the secondary side of the main transformer to regulate voltage by magnetic
pulse width modulation (PWM). The Mag-amp method is especially effective and economically attractive in
low voltage/high current circuits and is frequently used in power supplies for information processing
equipment, such as desktop PCs and computer servers, in power supplies for office equipment such as
photocopy machines and printers, and in power supplies for communication equipment, such as mobile
phone stations.
Miniaturization, high efficiency, low noise, high reliability, and high precision can be easily realized by adopting
the Mag-amp method.
Utilizing the unique magnetic characteristics of cobalt-based amorphous alloys, we have realized low loss at
high frequencies which cannot be realized using other materials. Our lineup consists of MS series cores,
which are well suited for general purpose applications, and MT cores, which have lower loss than the MS
series.
3. Saturable Cores for Mag-Amps
3. Saturable Cores for Mag-Amps
Standard Specifications
MT / MS Series
MT / MS Series
MT Series
MS Series
Type No.
MS7X4X3W
MS10X7X4.5W
MS12X8X4.5W
MS12X8X4.5W-HF
MS14X8X4.5W
MS15X10X4.5W
MS16X10X6W
MS18X12X4.5W
MS21X14X4.5W
MS26X16X4.5W
MS12X8X3W
MS15X10X3W
9.1
11.5
13.8
13.8
15.8
16.8
17.8
19.8
22.8
29.5
max
13.7
16.7
3.3
5.8
6.8
6.8
6.8
8.8
8.3
10.8
12.8
13.0
min
6.4
8.4
4.8
6.6
6.6
6.6
6.6
6.6
8.1
6.6
6.6
8.0
max
4.8
4.8
7.5
10
12
12
14
15
16
18
21
26
12
15
4.5
7
8
8
8
10
10
12
14
16
8
10
3.0
4.5
4.5
4.5
4.5
4.5
6.0
4.5
4.5
4.5
3.0
3.0
3.38
5.06
6.75
6.75
10.1
8.44
13.5
10.1
11.8
16.9
4.50
5.63
18.8
26.7
31.4
31.4
34.6
39.3
40.8
47.1
55.0
65.9
31.4
39.3
3.15
4.73
6.31
6.31
9.46
7.88
12.6
9.46
11.0
15.8
4.20
5.25
25 max 94 min
23
116
215
215
323
457
649
834
1371
2097
126
277
A
A
A
D
A
A
B
A
A
B
C
C
Basic Circuit Diagram of Mag-Amp method
AB
MT
Mag-Amp
out put
DC
B[T]
H[A/m]
B-H Curve （500kHz, RT)
100
1,000
10,000
100,000
100 1,000
Frequency [kHz]
Core Loss Pfe [kW/m3]
MS
MT
B=±0.2T, RT
MS
MT
0
-0.2
-0.4
-0.6
-300 -200 -100 100 200 300
Basic Characteristics（Typical Value）
Core Loss
0.6
0.4
0.2
MT12S115
MT12S208
MT15S125
MT15S214
MT18S130
MT18S222
MT21S134
MT21S222
MT12X 8X4.5W
MT15X10X4.5W
MT18X12X4.5W
MT21X14X4.5W
1.0
0.9
1.0
0.9
1.0
0.9
1.0
0.9
Wire
Diameter
φ[mm]
Core Type No.Type No.
Type No.
Parallel
Number
N
[turn]
Flux*1*2
[μWb]
Example of Circuit (150kHz)*3
Vo [V] Io [A]
Lead Length
C [mm]
Length of
Non Solder Package
1
2
1
2
1
2
1
2
15
8
25
14
30
22
34
22
94.7
50.5
197
110
284
208
375
243
5
3
12
5
15
12
24
15
6
10
6
10
6
10
6
10
20
20
25
25
28
28
32
32
13
13
15
15
15
15
15
15
20±5 3 max 1,000
[pcs in
a box]
D [mm]
.3
Type of wire
：1UEW
D
C
soldered
A
B
MS
MT
0.0 0.5 1.0 1.5 2.0
50
40
30
20
10
0
Core temperature rise ΔT[℃]
Output current Io[A]
280kHz,15V
Comparison of Core Temperature Rise in a Power Supply
A max B max
O.D.
*2
Core Size
*
5
[mm]
φc[μWb]min
Hc[A/m]
φc･AW
[μWb･mm2]
H.T. H.T.
Total Flux
*2
Br/Bm[%]
*2
Insulating
Covers
*
6
MT Standard Wired Series
*1 The amount of magnetic flux is equal to (Ｎ) ×(φc ).
*2 Measuring condition : 100kHz, 80A/m (sine wave), R.T.
*3 Recommend for designing (note : A design of a transformer in the case may be unable to use this data. Please set up the operating magnetic
flux 70% or less of the magnetic flux.)
*4 Dimensions of the Finished Insulating Covers ; Tolerance : ±0.2mm *5 Reference value
*6 Insulating cover is made with UL94V-0 approved material A : Black PET, B : Black PBT, C : Red LCP, D : Halogen-free
☆ Those other than standard winded articles can be manufactured. Please ask to sales department.
☆ MT sample kits are prepared. Please ask to sales department.
I.D. I.D. Ae [mm2]
Mean Flux
Path Length
Effective Core
Cross Section
*5
Lm [mm]
*5
Coercive
Force
Rectangular
Ratio
O.D.
Finished
Dimensions [mm]
Finished
Dimensions
*
4 [mm]
94 min20 max
Finished
Dimensions
*
4[mm]
I.D.
Core Size
*
5
[mm]
Ae [mm2]
Mean flux
Path Length φc[μWb]min
Hc[A/m]
φc･AW
[μWb･mm2]
Type No.
O.D.
Effective Core
Cross Section
*5
Lm [mm]
Total Flux
*
2
Br/Bm[%]
*2
*2
Insulating
Covers
*
6
H.T.
H.T. I.D. *5
Coercive
Force
Rectangular
Ratio
O.D.
MT10X7X4.5W
MT12X8X4.5W
MT14X8X4.5W
MT15X10X4.5W
MT16X10X6W
MT18X12X4.5W
MT21X14X4.5W
MT12X8X3W
MT15X10X3W
11.5
13.8
15.8
16.8
17.8
19.8
22.8
13.7
16.7
5.8
6.
6.8
8.8
8.3
10.8
12.8
6.4
8.4
6.6
6.6
6.6
6.6
8.1
6.6
6.6
4.8
4.8
10
12
14
15
16
18
21
12
15
7
8
8
10
10
12
14
8
10
4.5
4.5
4.5
4.5
6.0
4.5
4.5
3.0
3.0
5.06
6.75
10.1
8.44
13.5
10.1
11.8
4.50
5.63
26.7
31.4
34.6
39.3
40.8
47.1
55.0
31.4
39.3
4.73
6.31
9.46
7.88
12.6
9.46
11.0
4.20
5.25
116
215
323
457
649
834
1371
126
277
A
A
A
A
B
A
A
C
C
RoHS compliant products
RoHS compliant products
− 11 −
The Mag-amp method is one of several output voltage regulation methods used in switching power supplies.
A saturable core is used in the secondary side of the main transformer to regulate voltage by magnetic
pulse width modulation (PWM). The Mag-amp method is especially effective and economically attractive in
low voltage/high current circuits and is frequently used in power supplies for information processing
equipment, such as desktop PCs and computer servers, in power supplies for office equipment such as
photocopy machines and printers, and in power supplies for communication equipment, such as mobile
phone stations.
Miniaturization, high efficiency, low noise, high reliability, and high precision can be easily realized by adopting
the Mag-amp method.
Utilizing the unique magnetic characteristics of cobalt-based amorphous alloys, we have realized low loss at
high frequencies which cannot be realized using other materials. Our lineup consists of MS series cores,
which are well suited for general purpose applications, and MT cores, which have lower loss than the MS
series.
3. Saturable Cores for Mag-Amps
3. Saturable Cores for Mag-Amps
Standard Specifications
MT / MS Series
MT / MS Series
MT Series
MS Series
Type No.
MS7X4X3W
MS10X7X4.5W
MS12X8X4.5W
MS12X8X4.5W-HF
MS14X8X4.5W
MS15X10X4.5W
MS16X10X6W
MS18X12X4.5W
MS21X14X4.5W
MS26X16X4.5W
MS12X8X3W
MS15X10X3W
9.1
11.5
13.8
13.8
15.8
16.8
17.8
19.8
22.8
29.5
max
13.7
16.7
3.3
5.8
6.8
6.8
6.8
8.8
8.3
10.8
12.8
13.0
min
6.4
8.4
4.8
6.6
6.6
6.6
6.6
6.6
8.1
6.6
6.6
8.0
max
4.8
4.8
7.5
10
12
12
14
15
16
18
21
26
12
15
4.5
7
8
8
8
10
10
12
14
16
8
10
3.0
4.5
4.5
4.5
4.5
4.5
6.0
4.5
4.5
4.5
3.0
3.0
3.38
5.06
6.75
6.75
10.1
8.44
13.5
10.1
11.8
16.9
4.50
5.63
18.8
26.7
31.4
31.4
34.6
39.3
40.8
47.1
55.0
65.9
31.4
39.3
3.15
4.73
6.31
6.31
9.46
7.88
12.6
9.46
11.0
15.8
4.20
5.25
25 max 94 min
23
116
215
215
323
457
649
834
1371
2097
126
277
A
A
A
D
A
A
B
A
A
B
C
C
Basic Circuit Diagram of Mag-Amp method
AB
MT
Mag-Amp
out put
DC
B[T]
H[A/m]
B-H Curve （500kHz, RT)
100
1,000
10,000
100,000
100 1,000
Frequency [kHz]
Core Loss Pfe [kW/m3]
MS
MT
B=±0.2T, RT
MS
MT
0
-0.2
-0.4
-0.6
-300 -200 -100 100 200 300
Basic Characteristics（Typical Value）
Core Loss
0.6
0.4
0.2
MT12S115
MT12S208
MT15S125
MT15S214
MT18S130
MT18S222
MT21S134
MT21S222
MT12X 8X4.5W
MT15X10X4.5W
MT18X12X4.5W
MT21X14X4.5W
1.0
0.9
1.0
0.9
1.0
0.9
1.0
0.9
Wire
Diameter
φ[mm]
Core Type No.Type No.
Type No.
Parallel
Number
N
[turn]
Flux*1*2
[μWb]
Example of Circuit (150kHz)*3
Vo [V] Io [A]
Lead Length
C [mm]
Length of
Non Solder Package
1
2
1
2
1
2
1
2
15
8
25
14
30
22
34
22
94.7
50.5
197
110
284
208
375
243
5
3
12
5
15
12
24
15
6
10
6
10
6
10
6
10
20
20
25
25
28
28
32
32
13
13
15
15
15
15
15
15
20±5 3 max 1,000
[pcs in
a box]
D [mm]
.3
Type of wire
：1UEW
D
C
soldered
A
B
MS
MT
0.0 0.5 1.0 1.5 2.0
50
40
30
20
10
0
Core temperature rise ΔT[℃]
Output current Io[A]
280kHz,15V
Comparison of Core Temperature Rise in a Power Supply
A max B max
O.D.
*2
Core Size
*
5
[mm]
φc[μWb]min
Hc[A/m]
φc･AW
[μWb･mm2]
H.T. H.T.
Total Flux
*2
Br/Bm[%]
*2
Insulating
Covers
*
6
MT Standard Wired Series
*1 The amount of magnetic flux is equal to (Ｎ) ×(φc ).
*2 Measuring condition : 100kHz, 80A/m (sine wave), R.T.
*3 Recommend for designing (note : A design of a transformer in the case may be unable to use this data. Please set up the operating magnetic
flux 70% or less of the magnetic flux.)
*4 Dimensions of the Finished Insulating Covers ; Tolerance : ±0.2mm *5 Reference value
*6 Insulating cover is made with UL94V-0 approved material A : Black PET, B : Black PBT, C : Red LCP, D : Halogen-free
☆ Those other than standard winded articles can be manufactured. Please ask to sales department.
☆ MT sample kits are prepared. Please ask to sales department.
I.D. I.D. Ae [mm2]
Mean Flux
Path Length
Effective Core
Cross Section
*5
Lm [mm]
*5
Coercive
Force
Rectangular
Ratio
O.D.
Finished
Dimensions
[mm]
Finished
Dimensions
*
4 [mm]
94 min20 max
Finished
Dimensions
*
4
[mm]
I.D.
Core Size
*
5
[mm]
Ae [mm2]
Mean flux
Path Length φc[μWb]min
Hc[A/m]
φc･AW
[μWb･mm2]
Type No.
O.D.
Effective Core
Cross Section
*5
Lm [mm]
Total Flux
*
2
Br/Bm[%]
*2
*2
Insulating
Covers
*
6
H.T.
H.T.
I.D. *5
Coercive
Force
Rectangular
Ratio
O.D.
MT10X7X4.5W
MT12X8X4.5W
MT14X8X4.5W
MT15X10X4.5W
MT16X10X6W
MT18X12X4.5W
MT21X14X4.5W
11.5
13.8
15.8
16.8
17.8
19.8
22.8
5.8
6.
6.8
8.8
8.3
10.8
12.8
6.6
6.6
6.6
6.6
8.1
6.6
6.6
10
12
14
15
16
18
21
7
8
8
10
10
12
14
4.5
4.5
4.5
4.5
6.0
4.5
4.5
5.06
6.75
10.1
8.44
13.5
10.1
11.8
26.7
31.4
34.6
39.3
40.8
47.1
55.0
4.73
6.31
9.46
7.88
12.6
9.46
11.0
116
215
323
457
649
834
1371
A
A
A
A
B
A
A
RoHS
compliant products
RoHS
compliant products
− 12 −
- 6 - - 7 -
Merits of the Mag-Amp Method
Merits of the Mag-Amp Method
Since the Mag-amp method uses saturable cores to regulate voltage, there is a big advantage that cannot be achieved by
semiconductor-based regulation methods. The advantage is especially clear when there are large changes in the current.
As seen above, when the Mag-amp method is used in regulating output voltage of switching power supplies, excellent
characteristics can be achieved in size, efficiency, noise, reliability, and precision. Advantages in cost performance are
especially realized in low voltage / high current circuits (example: 3.3Vｰ5A).
Full Mag-Amp Method Cross-Regulation (Master-Slave) Method
Saturable Core MS Core Loss
Core Loss Pfe [kW/m3]
10
1
100
1000
10000
0.01 0.1 1
50kHz
100kHz
200kHz
300kHz
500kHz
Bm vs. Temperature
0
100
200
300
400
500
600
700
800
900
1000
-40 -20 0 20 40 60 80 100 120
Temperature [℃] Temperature [℃]Temperature [℃]
Bm [mT]
Typical Value
f=100kHz
Hm=80A/m
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
-40 -20 0 20 40 60 80 100 120
Hc vs. Temperature
Hc [A/m]
Typical Value
f=100kHz
Hm=80A/m
MT
MS
Br/Bm vs. Temperature
60
70
80
90
100
-40 -20 0 20 40 60 80 100 120
Br/Bm [%]
Typical Value
f=100kHz
Hm=80A/m
Mag-Amp
Mag-Amp
Mag-Amp
Mag-Amp
Mag-Amp
Large currents can be handled by small size cores. Also, there is no need for a heat sink and the number
of parts as the regulation circuit is small. This results in a smaller mount area compared to
semiconductor-based methods.
Miniaturization
(Downsizing)
Power Saving
Low Noise
High Reliability
High Precision
Forward Converter (ON-ON Type）
Mag-Amp Mag-Amp
Mag-Amp Mag-Amp
Mag-Amp
Flyback converter (ON-OFF Type）
Ringing choke converter（RCC) Full bridge converter
Half Bridge Converter
Push-pull converter（Center tap type）
Examples of Circuit
Characteristics (Typical Value)
Hc vs. Frequency
0
20
40
60
80
100
120
140
10 100 1000
frequency [kHz]
Hc [A/m ]
50 500
Typical Value
Room Temp.
Hm=200A/m
Sine Wave MT
MS
Saturable Core MT Core Loss
Core Loss Pfe [kW/m3]
10
1
100
1000
10000
0.01 0.1 1
100kHz
200kHz
300kHz
500kHz
The simple Mag-amp method is used mainly for voltage control of the post circuit in power supplies, called the
cross-regulation (master-slave) method. This cross-regulation method stabilizes the output voltage by feedback of the main
circuit to the primary side. Therefore, the post circuit output is affected by the situation of the load in the main circuit (cross
regulation error). There is also the problem that power supplies do not operate unless some current (minimum current) is sent
through the main circuit.
The Full Mag-amp method is a way to solve this problem.
The Full Mag-amp method controls each output at the secondary side. Therefore, there is no need for feedback to the primary
side, and each output can be controlled from no-load conditions. Also, since each output operates independently, the
optimization of the winding ratio for the main transformer and high efficiency can be realized compared to the
cross-regulation method.
Furthermore, since each output is independent in the Full Mag-amp method, it is only necessary to adjust the circuit where
the specification was changed. Therefore, time can be saved in the process of a design change.
Full Mag-Amp Method
Examples of Circuits and Characteristics
Examples of Circuits and Characteristics
Typical Value
Room Temp.
Sine Wave
Typical Value
Room Temp.
Sine Wave
Magnetic flux density ｜ΔＢ｜［Ｔ］ Magnetic flux density｜ΔＢ｜［Ｔ］
MT／MS
MT／MS
Because cobalt-based amorphous alloy is used, the operating loss at high frequencies is small. Also, the
power needed for control of the Mag-amp is smaller, enabling power to be saved.
The noise from the output diode is small because the Mag-amp is connected in series with the output
diode. In semiconductor-based methods, since the number of switching elements increases, so also
does the noise.
Since Mag-amps are magnetic parts, the cores are not destroyed by surges in voltage and current. For
this reason, they have been used in power supplies requiring reliability such as those for electricity or
large computers.
The Mag-amps realize precise output voltage because the secondary side of the main transformer is
directly controlled. It is possible to conduct voltage torelance with high precision (±1%), from no-load
conditions to full-load conditions.
Resonancer for Switching Power Supply ( Partial Resonace Element ), CT Magnetic Sensor,
Transformer Core for Self-Invertor Oscillator, High Frequency Saturable Core for Current Delay or Timing Control
Examples of a use other than Mag-Amp :
AB
OSC. P.W.M
+12V
+5V
0A
015A
AC
AB
AB
+3.3V
010A
+12V
0A
+3.3V
010A
AB
OSC.
P.W.M
+5V
115A
AC
AB
AB
− 13 −
- 6 - - 7 -
Merits of the Mag-Amp Method
Merits of the Mag-Amp Method
Since the Mag-amp method uses saturable cores to regulate voltage, there is a big advantage that cannot be achieved by
semiconductor-based regulation methods. The advantage is especially clear when there are large changes in the current.
As seen above, when the Mag-amp method is used in regulating output voltage of switching power supplies, excellent
characteristics can be achieved in size, efficiency, noise, reliability, and precision. Advantages in cost performance are
especially realized in low voltage / high current circuits (example: 3.3Vｰ5A).
Full Mag-Amp Method Cross-Regulation (Master-Slave) Method
Saturable Core MS Core Loss
Core Loss Pfe [kW/m3]
10
1
100
1000
10000
0.01 0.1 1
50kHz
100kHz
200kHz
300kHz
500kHz
Bm vs. Temperature
0
100
200
300
400
500
600
700
800
900
1000
-40 -20 0 20 40 60 80 100 120
Temperature [℃] Temperature [℃]Temperature [℃]
Bm [mT]
Typical Value
f=100kHz
Hm=80A/m
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
-40 -20 0 20 40 60 80 100 120
Hc vs. Temperature
Hc [A/m]
Typical Value
f=100kHz
Hm=80A/m
MT
MS
Br/Bm vs. Temperature
60
70
80
90
100
-40 -20 0 20 40 60 80 100 120
Br/Bm [%]
Typical Value
f=100kHz
Hm=80A/m
Mag-Amp
Mag-Amp
Mag-Amp
Mag-Amp
Mag-Amp
Large currents can be handled by small size cores. Also, there is no need for a heat sink and the number
of parts as the regulation circuit is small. This results in a smaller mount area compared to
semiconductor-based methods.
Miniaturization
(Downsizing)
Power Saving
Low Noise
High Reliability
High Precision
Forward Converter (ON-ON Type）
Mag-Amp Mag-Amp
Mag-Amp Mag-Amp
Mag-Amp
Flyback converter (ON-OFF Type）
Ringing choke converter（RCC) Full bridge converter
Half Bridge Converter
Push-pull converter（Center tap type）
Examples of Circuit
Characteristics (Typical Value)
Hc vs. Frequency
0
20
40
60
80
100
120
140
10 100 1000
frequency [kHz]
Hc [A/m ]
50 500
Typical Value
Room Temp.
Hm=200A/m
Sine Wave MT
MS
Saturable Core MT Core Loss
Core Loss Pfe [kW/m3]
10
1
100
1000
10000
0.01 0.1 1
100kHz
200kHz
300kHz
500kHz
The simple Mag-amp method is used mainly for voltage control of the post circuit in power supplies, called the
cross-regulation (master-slave) method. This cross-regulation method stabilizes the output voltage by feedback of the main
circuit to the primary side. Therefore, the post circuit output is affected by the situation of the load in the main circuit (cross
regulation error). There is also the problem that power supplies do not operate unless some current (minimum current) is sent
through the main circuit.
The Full Mag-amp method is a way to solve this problem.
The Full Mag-amp method controls each output at the secondary side. Therefore, there is no need for feedback to the primary
side, and each output can be controlled from no-load conditions. Also, since each output operates independently, the
optimization of the winding ratio for the main transformer and high efficiency can be realized compared to the
cross-regulation method.
Furthermore, since each output is independent in the Full Mag-amp method, it is only necessary to adjust the circuit where
the specification was changed. Therefore, time can be saved in the process of a design change.
Full Mag-Amp Method
Examples of Circuits and Characteristics
Examples of Circuits and Characteristics
Typical Value
Room Temp.
Sine Wave
Typical Value
Room Temp.
Sine Wave
Magnetic flux density ｜ΔＢ｜［Ｔ］ Magnetic flux density｜ΔＢ｜［Ｔ］
MT／MS
MT／MS
Because cobalt-based amorphous alloy is used, the operating loss at high frequencies is small. Also, the
power needed for control of the Mag-amp is smaller, enabling power to be saved.
The noise from the output diode is small because the Mag-amp is connected in series with the output
diode. In semiconductor-based methods, since the number of switching elements increases, so also
does the noise.
Since Mag-amps are magnetic parts, the cores are not destroyed by surges in voltage and current. For
this reason, they have been used in power supplies requiring reliability such as those for electricity or
large computers.
The Mag-amps realize precise output voltage because the secondary side of the main transformer is
directly controlled. It is possible to conduct voltage torelance with high precision (±1%), from no-load
conditions to full-load conditions.
Resonancer for Switching Power Supply ( Partial Resonace Element ), CT Magnetic Sensor,
Transformer Core for Self-Invertor Oscillator, High Frequency Saturable Core for Current Delay or Timing Control
Examples of a use other than Mag-Amp :
AB
OSC. P.W.M
+12V
+5V
0A
015A
AC
AB
AB
+3.3V
010A
+12V
0A
+3.3V
010A
AB
OSC.
P.W.M
+5V
115A
AC
AB
AB
− 14 −
- 14 - - 15 -
After suitable heat treatment has been done, cobalt base amorphous material shows excellent magnetic
properties. TOSHIBA MATERIALS has developed new high permeability core 'FS Series' with this material.
FS series maintain high initial permeability μi especially at the high frequency zone, and are suitable for
Pulse Transformers, Noise Filter and Cores for Sensors. High permeability enables electronic parts to be
smaller and have higher performance.
Standard Specifications
Applications
FS Series
FS Series
High Permeability : μi at 10kHz is 100,000 it changes inductance module smaller and higher performance.
Low Loss : Smaller core loss, higher exchange efficiency, lower self heat of core can be obtained.
Constant Permeability : Small permeability change depending on magnetic field.
Thin and Small Core : Small miniature core enables to mount in a PC-card.
ADSL modem, or
pulse transformer for terminal adapter
PC
Telephone
FS
AB
FS
Type No.
Finished Dimensions [mm]
I.D.min
14.0
20.0
23.0
29.5
35.5
6.6
10.6
12.6
13.0
17.0
H.T.max
6.8
6.8
6.8
13.0
13.0
O.D.max
Core Size [mm]
O.D. I.D. H.T.
12
18
21
26
32
8
12
14
16
20
4.5
4.5
4.5
9.5
9.5
Effective core
cross section
Ae [mm2]
Mean flux
path length
Lm [mm]
AL Value
[μH/n2]
Insulating
Cover
A
A
A
B
B
27.0
27.0
27.0
67.8
65.7
31.4
47.1
55.0
66.0
81.7
6.75
10.1
11.8
35.6
42.8
Operating temperature has to be less than 85℃ (include self rise up)
巻数 １ターン
1 10 100 1000 10000
10
1
0.1
100
Impedance [Ω/n2 ]
0.8
0.6
0.4
0.2
-0.2
-0.4
-0.6
-0.8
-10 -5 5 10
Ｂ [Ｔ］
H [A/m]
DC BH Curve
FS32×20×10W
FS26×16×10W
FS12×8×4.5W
FS18×12×4.5W
FS21×14×4.5W
4．High Magnetic Permeability Cores for Pulse Transformer
4．High Magnetic Permeability Cores for Pulse Transformer
Characteristics (Typical Value)
10,000
1,000
100
100,000
1,000,000
1 10 100 1000 10000
FS
Ferrite
Specific Permeability
Frequency vs. Permeability
Frequency [kHz]
Frequency [kHz]
Core Loss [kW/m3]
1
10
100
1000
10000
10 100 1000
ＦＳ
Ferrite
Frequency [kHz]
Core Loss VS. Frequency
10
1
0.1
100
1000
1 10 100 1000 10000
ALVaue [μH/n2]
FS32×20×10W
FS26×16×10W
FS12×8×4.5W
FS18×12×4.5W
FS21×14×4.5W
Frequency [kHz]
AL Value VS. Frequency
Impedance VS. Frequency
＊1 ＊1 ＊1 ＊2 ＊3 ＊4
＊1 Reference value ＊2 Tolerance±30% ＊3 Measuring Condition : 10kHz,10mA, 1turn, R.T.
＊4 Insulating cover made with UL94V-0 Approved Material.
A: PET, B: PBT
Don't hesitate to ask our sales section about other size items.
☆Magnetic core of pulse transformer
Communication instrument (ADSL etc.)
Small size, high density assemble
☆Magnetic core for common mode noise filter
Switching power supply
Communication and measuring instrument
☆Magnetic core for current transformer
Common mode noize filter
for switching power supply
RoHS compliant products
RoHS compliant products
DC Bias Characteristic
100
10
1
10 100 1000
FS18×12×4.5W
FS12×8×4.5W
FS21×14×4.5W
FS26×16×10W
FS32×20×10W
AL Value [μH/n2]
DC [mA]
FS12X8X4.5W
FS18X12X4.5W
FS21X14X4.5W
FS26X16X10W
FS32X20X10W
− 15 −
- 14 - - 15 -
After suitable heat treatment has been done, cobalt base amorphous material shows excellent magnetic
properties. TOSHIBA MATERIALS has developed new high permeability core 'FS Series' with this material.
FS series maintain high initial permeability μi especially at the high frequency zone, and are suitable for
Pulse Transformers, Noise Filter and Cores for Sensors. High permeability enables electronic parts to be
smaller and have higher performance.
Standard Specifications
Applications
FS Series
FS Series
High Permeability : μi at 10kHz is 100,000 it changes inductance module smaller and higher performance.
Low Loss : Smaller core loss, higher exchange efficiency, lower self heat of core can be obtained.
Constant Permeability : Small permeability change depending on magnetic field.
Thin and Small Core : Small miniature core enables to mount in a PC-card.
ADSL modem, or
pulse transformer for terminal adapter
PC
Telephone
FS
AB
FS
Type No.
Finished Dimensions [mm]
I.D.min
14.0
20.0
23.0
29.5
35.5
6.6
10.6
12.6
13.0
17.0
H.T.max
6.8
6.8
6.8
13.0
13.0
O.D.max
Core Size [mm]
O.D. I.D. H.T.
12
18
21
26
32
8
12
14
16
20
4.5
4.5
4.5
9.5
9.5
Effective core
cross section
Ae [mm2]
Mean flux
path length
Lm [mm]
AL Value
[μH/n2]
Insulating
Cover
A
A
A
B
B
27.0
27.0
27.0
67.8
65.7
31.4
47.1
55.0
66.0
81.7
6.75
10.1
11.8
35.6
42.8
Operating temperature has to be less than 85℃ (include self rise up)
巻数 １ターン
1 10 100 1000 10000
10
1
0.1
100
Impedance [Ω/n2]
0.8
0.6
0.4
0.2
-0.2
-0.4
-0.6
-0.8
-10 -5 5 10
Ｂ [Ｔ］
H [A/m]
DC BH Curve
FS32×20×10W
FS26×16×10W
FS12×8×4.5W
FS18×12×4.5W
FS21×14×4.5W
4．High Magnetic Permeability Cores for Pulse Transformer
4．High Magnetic Permeability Cores for Pulse Transformer
Characteristics (Typical Value)
10,000
1,000
100
100,000
1,000,000
1 10 100 1000 10000
FS
Ferrite
Specific Permeability
Frequency vs. Permeability
Frequency [kHz]
Frequency [kHz]
Core Loss [kW/m3]
1
10
100
1000
10000
10 100 1000
ＦＳ
Ferrite
Frequency [kHz]
Core Loss VS. Frequency
10
1
0.1
100
1000
1 10 100 1000 10000
ALVaue [μH/n2]
FS32×20×10W
FS26×16×10W
FS12×8×4.5W
FS18×12×4.5W
FS21×14×4.5W
Frequency [kHz]
AL Value VS. Frequency
Impedance VS. Frequency
＊1 ＊1 ＊1 ＊2 ＊3 ＊4
＊1 Reference value ＊2 Tolerance±30% ＊3 Measuring Condition : 10kHz,10mA, 1turn, R.T.
＊4 Insulating cover made with UL94V-0 Approved Material.
A: PET, B: PBT
Don't hesitate to ask our sales section about other size items.
☆Magnetic core of pulse transformer
Communication instrument (ADSL etc.)
Small size, high density assemble
☆Magnetic core for common mode noise filter
Switching power supply
Communication and measuring instrument
☆Magnetic core for current transformer
Common mode noize filter
for switching power supply
RoHS
compliant products
RoHS
compliant products
DC Bias Characteristic
100
10
1
10 100 1000
FS18×12×4.5W
FS12×8×4.5W
FS21×14×4.5W
FS26×16×10W
FS32×20×10W
AL Value [μH/n2]
DC [mA]
FS12X8X4.5W
FS18X12X4.5W
FS21X14X4.5W
FS26X16X10W
FS32X20X10W
− 16 −
- 20 - - 21 -
How to Select the Proper Size "AMOBEADSTM "
How to Select the Proper Size "AMOBEADSTM "
Principle of the Noise Suppressing Device
Principle of the Noise Suppressing Device
We will explain the behavior of "AMOBEADSTM " when slipped over the lead of a switching power supply
output diode.
PeriodⅠ, 0 (When Diode is On)
During period I, which is when the diode is in the "ON" condition and the forward current is running, the
"AMOBEADSTM " are in the saturated magnetic condition "I". There will be almost no inductance under
this condition. (Inductance is proportional to the slope of the B-H curve.)
PeriodⅡ(When Diode is Turn Off)
During period Ⅱ, which is when the diode current starts to turn off and the current decreases heading
towards zero, the "AMOBEADSTM " magnetization curve will change like "Ⅱ" in a condition of almost no
inductance until the current crosses zero. Since there is no inductance during this period Ⅱ, the angle
or slope of the diode current during turn off is constant, a unique characteristic of the "AMOBEADSTM ".
If materials such as ferrite is used, inductance will occur during this period Ⅱ and the angle or slope of
current during the turn off period will change and this will lead to increased of diode loss.
Period Ⅲ(Reverse Recovery Period)
During periodⅢ, a reverse recovery current tries to flow in a direction opposite to the normal direction of
current flow of the diode and as a result, the magnetization curve of the "AMOBEADSTM " change like "Ⅲ"
and the inductance increases rapidly. At this time, the large inductance of the "AMOBEADSTM "
intercepts and opposes the recovery current and converts the current into a soft recovery condition.
Thus by converting the sharp reverse recovery to a soft recovery condition by decreasing the rate of
the current change (di/dt), the "AMOBEADSTM " minimize the rapid change of current (High di/dt) and
suppress the noise in the circuit.
Period Ⅳ(After Reverse Recovery Ends)
During period Ⅳ, when the reverse recovery of the diode ends, the magnetization of the "AMOBEADSTM "
will move parallel to the vertical axis of the magnetization curve as shown in period "Ⅳ".
Period Ⅴ (When Diode is Turn On)
The "AMOBEADSTM " magnetization will change as shown in "Ⅴ" of the magnetization curve and go
back to a saturation condition. At this point, the diode will turn on and after a slight delay of the start
up of current, the next current pulse will develop and the cycle described above from Period Ⅰthru Ⅴ will
repeat itself.
As the complete cycle repeats itself at the circuit operating frequency, the "AMOBEADSTM " repeatedly
suppress circuit noise during period III of the cycle by eliminating the rapid change in the reverse
recovery current of the diode, which is the cause of noise.
"AMOBEADSTM " use a cobalt based amorphous alloy with a small coercive force under frequency and
this results in excellent noise suppression.
ⅠⅡ
Ⅲ
Ⅳ
Ⅴ
Forward Current
Reverse Current
Ⅰ
Ⅱ
Ⅲ
Ⅳ
Ⅴ
high di/dt
Soft Recovery by AMOBEADSTM
Ir=Hc×Lm/N
Actual BH Curve
trr
Flyback Converter
Example of "AMOBEADSTM " Selection
Example of Noise Reduction
Forward Converter
Output Voltage
trr 3.3V 5V 12V 15V 24V
35nsec AB3×2×3W AB3×2×4.5W AB3×2×6W AB4×2×4.5W AB4×2×6W
60nsec AB3×2×4.5W AB3×2×6W AB4×2×4.5W AB4×2×6W SPIKE KILLER
Output Voltage
trr 3.3V 5V 12V 15V 24V
35nsec AB3×2×3W AB3×2×3W AB3×2×4.5W AB3×2×6W AB4×2×4.5W
60nsec AB3×2×3W AB3×2×4.5W AB3×2×6W AB4×2×4.5W AB4×2×6W
Reverse Recovery
Without Countermeasure With AMOBEADS
(AB4×2×8W)
φ[Wb]
H (A/m)
Reference
Reference
The proper size "AMOBEADSTM " core is selected by calculating the necessary voltage times the
time in seconds (=flux). From its operating theory, there is a need to increase the voltage used in the
calculation by that which develops during the reverse recovery period of diode. The multiple of the
voltage and time (voltage times second) is equal to the operating flux. Therefore, the magnetization Δφ
ns necessary to suppress the noise is calculated by the voltage Ec[V] and time for reverse recovery of
diode, that is added to "AMOBEADSTM "
A good result is achieved when the voltage Ec added to "AMOBEADSTM " is close to voltage added to
diode. Please select the "AMOBEADSTM " that have a larger core magnetization φc than the voltage
times seconds that was calculated here. However, the actual noise suppression result for
"AMOBEADSTM " on real circuit may differ from the calculated value due to the peculiar recovery
characteristics of the diode used or the circuit structure. So please confirm the effect by performing
examination. "AMOBEADSTM " can be also affected by things like a CR snubber, so please perform
evaluation under condition without any effect of a snubber.
Since "AMOBEADSTM " have high circuit voltage, sometimes an insufficient result is obtained when the
reverse recovery time is long and has minimal magnetization. Under this condition, please consider a
wire wound type "SPIKE KILLERTM "
Δφns [Wb] ＝Ec×t rr［V×Sec]
Current Waveform of Diode
t
− 17 −
- 20 - - 21 -
How to Select the Proper Size "AMOBEADSTM "
How to Select the Proper Size "AMOBEADSTM "
Principle of the Noise Suppressing Device
Principle of the Noise Suppressing Device
We will explain the behavior of "AMOBEADSTM " when slipped over the lead of a switching power supply
output diode.
PeriodⅠ, 0 (When Diode is On)
During period I, which is when the diode is in the "ON" condition and the forward current is running, the
"AMOBEADSTM " are in the saturated magnetic condition "I". There will be almost no inductance under
this condition. (Inductance is proportional to the slope of the B-H curve.)
PeriodⅡ(When Diode is Turn Off)
During period Ⅱ, which is when the diode current starts to turn off and the current decreases heading
towards zero, the "AMOBEADSTM " magnetization curve will change like "Ⅱ" in a condition of almost no
inductance until the current crosses zero. Since there is no inductance during this period Ⅱ, the angle
or slope of the diode current during turn off is constant, a unique characteristic of the "AMOBEADSTM ".
If materials such as ferrite is used, inductance will occur during this period Ⅱ and the angle or slope of
current during the turn off period will change and this will lead to increased of diode loss.
Period Ⅲ(Reverse Recovery Period)
During periodⅢ, a reverse recovery current tries to flow in a direction opposite to the normal direction of
current flow of the diode and as a result, the magnetization curve of the "AMOBEADSTM " change like "Ⅲ"
and the inductance increases rapidly. At this time, the large inductance of the "AMOBEADSTM "
intercepts and opposes the recovery current and converts the current into a soft recovery condition.
Thus by converting the sharp reverse recovery to a soft recovery condition by decreasing the rate of
the current change (di/dt), the "AMOBEADSTM " minimize the rapid change of current (High di/dt) and
suppress the noise in the circuit.
Period Ⅳ(After Reverse Recovery Ends)
During period Ⅳ, when the reverse recovery of the diode ends, the magnetization of the "AMOBEADSTM "
will move parallel to the vertical axis of the magnetization curve as shown in period "Ⅳ".
Period Ⅴ (When Diode is Turn On)
The "AMOBEADSTM " magnetization will change as shown in "Ⅴ" of the magnetization curve and go
back to a saturation condition. At this point, the diode will turn on and after a slight delay of the start
up of current, the next current pulse will develop and the cycle described above from Period Ⅰ thru Ⅴ will
repeat itself.
As the complete cycle repeats itself at the circuit operating frequency, the "AMOBEADSTM " repeatedly
suppress circuit noise during period III of the cycle by eliminating the rapid change in the reverse
recovery current of the diode, which is the cause of noise.
"AMOBEADSTM " use a cobalt based amorphous alloy with a small coercive force under frequency and
this results in excellent noise suppression.
ⅠⅡ
Ⅲ
Ⅳ
Ⅴ
Forward Current
Reverse Current
Ⅰ
Ⅱ
Ⅲ
Ⅳ
Ⅴ
high di/dt
Soft Recovery by AMOBEADSTM
Ir=Hc×Lm/N
Actual BH Curve
trr
Flyback Converter
Example of "AMOBEADSTM " Selection
Example of Noise Reduction
Forward Converter
Output Voltage
trr 3.3V 5V 12V 15V 24V
35nsec AB3×2×3W AB3×2×4.5W AB3×2×6W AB4×2×4.5W AB4×2×6W
60nsec AB3×2×4.5W AB3×2×6W AB4×2×4.5W AB4×2×6W SPIKE KILLER
Output Voltage
trr 3.3V 5V 12V 15V 24V
35nsec AB3×2×3W AB3×2×3W AB3×2×4.5W AB3×2×6W AB4×2×4.5W
60nsec AB3×2×3W AB3×2×4.5W AB3×2×6W AB4×2×4.5W AB4×2×6W
Reverse Recovery
Without Countermeasure With AMOBEADS
(AB4×2×8W)
φ[Wb]
H (A/m)
Reference
Reference
The proper size "AMOBEADSTM " core is selected by calculating the necessary voltage times the
time in seconds (=flux). From its operating theory, there is a need to increase the voltage used in the
calculation by that which develops during the reverse recovery period of diode. The multiple of the
voltage and time (voltage times second) is equal to the operating flux. Therefore, the magnetization Δφ
ns necessary to suppress the noise is calculated by the voltage Ec[V] and time for reverse recovery of
diode, that is added to "AMOBEADSTM "
A good result is achieved when the voltage Ec added to "AMOBEADSTM " is close to voltage added to
diode. Please select the "AMOBEADSTM " that have a larger core magnetization φc than the voltage
times seconds that was calculated here. However, the actual noise suppression result for
"AMOBEADSTM " on real circuit may differ from the calculated value due to the peculiar recovery
characteristics of the diode used or the circuit structure. So please confirm the effect by performing
examination. "AMOBEADSTM " can be also affected by things like a CR snubber, so please perform
evaluation under condition without any effect of a snubber.
Since "AMOBEADSTM " have high circuit voltage, sometimes an insufficient result is obtained when the
reverse recovery time is long and has minimal magnetization. Under this condition, please consider a
wire wound type "SPIKE KILLERTM "
Δφns [Wb] ＝Ec×t rr［V×Sec]
Current Waveform of Diode
t
− 18 −
- 16 - - 17 -
☆ Flux needed for mag-amp control
The calculation of the Voltage-time product (=Magnetic Flux) Δφmag differs between when the mag-amp is
used for voltage regulation only and when the mag-amp is also used to protect against over currents.
（1）Voltage regulation
The mag-amp is designed with the standard of no
load, because the flux deviation is usually largest
when there is no load. The coefficient for the
incremental increase in voltage at no load (Kv) is
used. (Kv=<1)
Δφmag＝ΔφV2×Kv [Wb]
（2）Protection of over currents
When the mag-amp is also used to protect
against over-currents, the on-pulse maximum
voltage-time productΔφv2must be handled by the
mag-amp. Therefore, the following calculation is
applied.
Δφmag＝ΔφV2 [Wb]
☆Selection of core size
The core size is selected based on the flux needed to control the mag-amp, Δφmag. The following simplified
calculation is used to select core size.
φＣ･Aw ≧Δφmag×Io/(Kf×J) /Kt [Wb・mm2]
Here, φC is the total flux of the core and AW is the core winding area. The values for φC･Aw are found in the
standard specification chart. Kt is the design safety coefficient; Kf is the coefficient for wire winding, and J is
the current density.
☆Calculation of Number of Turn
The number of turns (Ｎ) is calculated by the following equation, where N is an integer.
N ≧Δφmag / φC min / Kt [turn]
☆Calculation of Diameter of the Wire
From the equation for current density J [A/mm2], wire diameterｄ[mm], output current Io[A],
Io＝(d/2)2×π×J [A] → d = 2× Io/(π×J) [mm]
H
B
Ⅰ
Ⅱ
Ⅲ
Ⅳ
BH cuve of the material
Secondary voltage
of the transformer
Voltage of Mag-Amp
Current of Mag-Amp
Period Ⅰ (Pulse is on)
When the "ON" pulse is from the main transformer, the flux changes as "Ⅰ" on the actual magnetization
curve. At this time, the saturable core has very high inductance because the core's magnetization is in
an unsaturated area. When voltage is added, it is handled at both ends of the coil and the current does
not flow toward the side with the current load. During Period "Ⅰ", the voltage is blocked with the switch
OFF, and the pulse width modulation is done.
Period Ⅱ (Mag-amp is saturation)
After some time at Period Ⅰ, the saturable core becomes saturated "Ⅱ" and the inductance rapidly
decreases to a minimum and the current is supplied toward the load side. The switch is ON in Period Ⅱ.
Period Ⅲ (Pulse is off)
When the pulse from the main transformer is OFF (Period Ⅲ), the magnetic curve of the saturable core
changes as in Ⅲ. It rises over the magnetization axis from the effects of the reverse recovery current
and leaked current of the output diode.
Period Ⅳ (Reset)
While the polarity of the pulse voltage is reversed (Period Ⅳ), there is voltage control which
corresponds with the preset output voltage by the Mag-amp control circuit. The saturable core's
magnetization changes (resets) itself as in "Ⅳ".
Period Ⅰ～Period Ⅳ is operated repeatedly through the operated frequency and the voltage is
regulated.
The reset area at Period Ⅳ and the area at Period Ⅰ is equal. Therefore, by changing the reset amount
at Period Ⅳ, the blocked area at Period Ⅰ can be changed, and it becomes possible to regulate voltage
by magnetic P.W.M.
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅲ
Ⅳ
Ⅰ
Ⅱ
Ⅲ
Ⅳ
Mag-Amp
E2
DON DOFF
E2
Vo
Io
Mag-Amp Operating Principle
Mag-Amp Design (Forward Converter)
Mag-Amp Operating Principle
Mag-Amp Design (Forward Converter)
The standard methodology for designing and selecting the proper size mag-amp is to first determine the
product of the secondary voltage of the transformer and the "on duty" time, measured in seconds. The
proper size mag-amp can then be selected by determining which mag-amp core can adequately handle the
highest product of this secondary voltage and "on duty" time, otherwise known as core flux. All
calculations must be made on the condition that this on-pulse product of voltage and time is at its
maximum.
☆ On-pulse maximum product of time
The on-pulse maximum product of time △φV2is calculated from the secondary voltage of the transformer
(=E2) [V] and the maximum on time duty period (=Don) and operating frequency (=f)[Hz]. For
cross-regulation type circuits, the on-duty values for the main circuit at maximum load current are usually
used.
Δφ
V2 [Wb]＝E2×DON／f [V×Sec]
Transformer Voltage［Ｖ］
Output Current［Ａ］
Transformer System
V0
Vh
Reference
ΔφV2
Reference
Vh
Vo
KV=
see
right figure
Output Current vs. Transformer Voltage
Mag-Amp Control
Please always confirm operation on the actual circuit after design.
Mag-Amp circuit of the secondary side Transformer voltage of the secondary side
Actual magnetization curve
The Mag-Amp method is a switching regulation method for D.C power supply in which the magnetic
switch is created through using saturated area and unsaturated area of the saturable core. Voltage
regulation at the secondary side of the switching supply is realized by P.W.M. (Pulse Width Modulation).
E2 ×T＝Δφ
Δφ
E2
T
− 19 −
- 16 - - 17 -
☆ Flux needed for mag-amp control
The calculation of the Voltage-time product (=Magnetic Flux) Δφmag differs between when the mag-amp is
used for voltage regulation only and when the mag-amp is also used to protect against over currents.
（1）Voltage regulation
The mag-amp is designed with the standard of no
load, because the flux deviation is usually largest
when there is no load. The coefficient for the
incremental increase in voltage at no load (Kv) is
used. (Kv=<1)
Δφmag＝ΔφV2×Kv [Wb]
（2）Protection of over currents
When the mag-amp is also used to protect
against over-currents, the on-pulse maximum
voltage-time productΔφv2 must be handled by the
mag-amp. Therefore, the following calculation is
applied.
Δφmag＝ΔφV2 [Wb]
☆Selection of core size
The core size is selected based on the flux needed to control the mag-amp, Δφmag. The following simplified
calculation is used to select core size.
φＣ･Aw ≧Δφmag×Io/(Kf×J) /Kt [Wb・mm2]
Here, φC is the total flux of the core and AW is the core winding area. The values for φC･Aw are found in the
standard specification chart. Kt is the design safety coefficient; Kf is the coefficient for wire winding, and J is
the current density.
☆Calculation of Number of Turn
The number of turns (Ｎ) is calculated by the following equation, where N is an integer.
N ≧Δφmag / φC min / Kt [turn]
☆Calculation of Diameter of the Wire
From the equation for current density J [A/mm2], wire diameterｄ[mm], output current Io[A],
Io＝(d/2)2×π×J [A] → d = 2× Io/(π×J) [mm]
H
B
Ⅰ
Ⅱ
Ⅲ
Ⅳ
BH cuve of the material
Secondary voltage
of the transformer
Voltage of Mag-Amp
Current of Mag-Amp
Period Ⅰ (Pulse is on)
When the "ON" pulse is from the main transformer, the flux changes as "Ⅰ" on the actual magnetization
curve. At this time, the saturable core has very high inductance because the core's magnetization is in
an unsaturated area. When voltage is added, it is handled at both ends of the coil and the current does
not flow toward the side with the current load. During Period "Ⅰ", the voltage is blocked with the switch
OFF, and the pulse width modulation is done.
Period Ⅱ (Mag-amp is saturation)
After some time at Period Ⅰ, the saturable core becomes saturated "Ⅱ" and the inductance rapidly
decreases to a minimum and the current is supplied toward the load side. The switch is ON in Period Ⅱ.
Period Ⅲ (Pulse is off)
When the pulse from the main transformer is OFF (Period Ⅲ), the magnetic curve of the saturable core
changes as in Ⅲ. It rises over the magnetization axis from the effects of the reverse recovery current
and leaked current of the output diode.
Period Ⅳ (Reset)
While the polarity of the pulse voltage is reversed (Period Ⅳ), there is voltage control which
corresponds with the preset output voltage by the Mag-amp control circuit. The saturable core's
magnetization changes (resets) itself as in "Ⅳ".
Period Ⅰ～Period Ⅳis operated repeatedly through the operated frequency and the voltage is
regulated.
The reset area at Period Ⅳ and the area at Period Ⅰis equal. Therefore, by changing the reset amount
at Period Ⅳ, the blocked area at Period Ⅰcan be changed, and it becomes possible to regulate voltage
by magnetic P.W.M.
Ⅰ
Ⅱ
Ⅰ
Ⅱ
Ⅲ
Ⅳ
Ⅰ
Ⅱ
Ⅲ
Ⅳ
Mag-Amp
E2
DON DOFF
E2
Vo
Io
Mag-Amp Operating Principle
Mag-Amp Design (Forward Converter)
Mag-Amp Operating Principle
Mag-Amp Design (Forward Converter)
The standard methodology for designing and selecting the proper size mag-amp is to first determine the
product of the secondary voltage of the transformer and the "on duty" time, measured in seconds. The
proper size mag-amp can then be selected by determining which mag-amp core can adequately handle the
highest product of this secondary voltage and "on duty" time, otherwise known as core flux. All
calculations must be made on the condition that this on-pulse product of voltage and time is at its
maximum.
☆ On-pulse maximum product of time
The on-pulse maximum product of time △φV2 is calculated from the secondary voltage of the transformer
(=E2) [V] and the maximum on time duty period (=Don) and operating frequency (=f)[Hz]. For
cross-regulation type circuits, the on-duty values for the main circuit at maximum load current are usually
used.
Δφ
V2 [Wb]＝E2×DON／f [V×Sec]
Transformer Voltage［Ｖ］
Output Current［Ａ］
Transformer System
V0
Vh
Reference
ΔφV2
Reference
Vh
Vo
KV=
see
right figure
Output Current vs. Transformer Voltage
Mag-Amp Control
Please always confirm operation on the actual circuit after design.
Mag-Amp circuit of the secondary side Transformer voltage of the secondary side
Actual magnetization curve
The Mag-Amp method is a switching regulation method for D.C power supply in which the magnetic
switch is created through using saturated area and unsaturated area of the saturable core. Voltage
regulation at the secondary side of the switching supply is realized by P.W.M. (Pulse Width Modulation).
E2 ×T＝Δφ
Δφ
E2
T
− 20 −
- 18 - - 19 -
Here, we show a design example when regulating a 5V-10A circuit using a forward converter with an
operating frequency of 150kHz.
☆On-pulse maximum voltage-time product
The E2 on the secondary side of the main transformer and the maximum on duty cycle are assumed to
be E2=15[V] and Don=0.4.
ΔφV2＝E2×Don／ｆ[V×Sec]＝[Wb]
＝15×0.4/150000
＝40 [μWb]
When using a Mag-amp to also protect against over currents, Δφmag＝ΔφV2. Here, we assume that the
mag-amp only regulates voltage and set the incremental increase at the time of no current load as
KV=0.6.
Δφmag＝ΔφV2×KV＝40×0.6＝24 [μWb]
☆Choice of core size
The wire winding coefficient, Kf, is the coefficient that it is possible to wind on the inside of a toroidal
core. Usually, Kf=0.4 is used. The current density J is usually set as J=5～10[A/mm2]. Here, we assume
J＝8[A/mm2].
If the mag-amp's maximum operating temperature is assumed to be 120℃, we assume that the flux
density of the core decreases to 80%. We also allow flux design space to be 70%.
φ
C･AW ≧Δφmag×Io/(Kf×J)/Kt
≧24×10/(0.4×8)/(0.8×0.7)
≧133.9 [μWb・mm2]
From the standard specification table, MT12X8X4.5W is chosen.
☆Number of wire winding
N≧Δφmag/φCmin/Kt [turn]
≧24/6.31/(0.8×0.7)＝6.8
＝7 [turn]
☆Wire diameter
When the wire diameter is over φ1.0mm, there is difficulty in the actual wire winding of the toroidal cores.
Therefore, when the output current Io is over 5[A], parallel winding is used. Here, since Io＝10[A], two
parallel wires are used.
d＝2× Io/2/(π×J) [mm]
＝2× 10/2/(π×8)＝0.89 [mm]
As a result, 2 parallel φ0.9mm wires are wound.
☆Results of design (Operating Frequency 150kHz, 5V-10A, Voltage Regulation)
MT12X8X4.5W, φ0.9mm, 2 parallel windings, 7[turn]
Please always confirm operation on the actual circuit after design. Since the mag-amp is a passive part,
it becomes susceptible to effects from the waves of the transformer, and actual operating tests are
necessary.
Examples of the Design
Evaluation of the Mag-Amp Circuit Unit
Examples of the Design
Evaluation of the Mag-Amp Circuit Unit
Note) Operating flux is influenced by the main transformer of the circuit, and the value shown in the table is not necessarily applied as it is.
Design Example ( Forward Converter, 150kHz operating）
Voltage Control（at Kv=0.6）
3.3V
5V
12V
15V
24V
MT12S115
MT12S115
MT15S125
MT15S125
MT18S130
MT12S208
MT12S208
MT15S214
MT18S222
MT18S222
Current 15A
（φ0.9mm×3p.）
MT12 : 5turn
MT15 : 6turn
MT18S311
MT18 :14turn
MT21 :19turn
Over Current Protection (at E2×DON =1.2Vo）
MT12S115
MT12S115
MT15S125
MT18S130
MT21S134
10A
（φ0.9mm×2p.）
MT15:7turn
MT16:6turn
MT21:16turn
MT21:20turn
MS26:18turn
MT12S208
MT15S214
MT18S222
MT21S222
MT21:32turn
6A
(φ1.0mm)
10A
（φ0.9mm×2p.）
6A
(φ1.0mm)
15A
（φ0.9mm×3p.）
Reference
Reference
Voltage
Output Current vs. Transformer Voltage
1）At no-Load
Generally, the range of the flux becomes large at no, or small current load. There is a possibility that
the mag-amp may not be able to control the output voltage because there is a shortage of core flux.
This problem occurs because the large range of the flux density causes saturating on the other side
and there is not enough ability to control the voltage-time product. In order to set the allowances for
design, the wire winding for the Mag-amp is reduced and the operating range is confirmed.
However, the core flux necessary at the time of no current load is largely influenced by such factors as
the dummy current value. Therefore, when the core flux is large at no current load, such factors as the
dummy current value must be adjusted, taking efficiency into account.
2）At Full-Load
Generally, the mag-amp's flux range becomes small at the full current load. There is the possibility that
output voltage cannot be regulated because it is not possible to make the range any smaller. This
problem is called the dead angle.
The allowances for design at full current load are confirmed by increasing the number of wire windings.
However, the dead angle value is influenced not only by the core characteristics, but also by the
reverse recovery current of the output diode and leaked currents. Please select output diodes with fast
recovery times. Also, when using SBD (Schottky Barrier Diode), please use one with small current leaks
and stable temperature characteristics.
3）Temperature Rise
The temperature rise from no current load to full current load should be confirmed. Since the upper limit
temperature for continuous use of our mag-amp saturable cores is 120℃, the mag-amp should be
designed so that the sum of the surrounding temperature and core temperature rise does not exceed
120℃. Please measure core temperature rise under the condition of natural air-cooling (Without
cooling fan). Generally, the mag-amp is designed calculating the temperature rise at ΔT＝30℃～40℃.
With forward converters, the temperature rise at no current load is especially high. When this occurs,
the wire winding should be increased and the operating flux density reduced. When the temperature
rise is too high at full current load, the wire winding should be reduced and the operating magnetic field
reduced.
4）Output voltage precision
It is necessary to confirm the voltage regulation characteristics (specifications) from no current load
to full current load conditions. When there is a mismatch between the gain of the mag-amp and the
gain of the regulated circuit, the circuit vibrates abnormally. Especially when there are sounds from the
mag-amp circuit, there is a high possibility that the regulated circuit is abnormally vibrating.
5）Protection from Over currents
When protecting for over currents, the range of operating flux for the mag-amp becomes large. Please
set the maximum flux range to be 70% of the core flux, similar to when there is no current load.
V0
Transformer Voltage [ V ]
Output Current [ A ]
Transformer
No load
Mag-Amp controlled
Dead Angle (ΔVd)
− 21 −
- 18 - - 19 -
Here, we show a design example when regulating a 5V-10A circuit using a forward converter with an
operating frequency of 150kHz.
☆On-pulse maximum voltage-time product
The E2on the secondary side of the main transformer and the maximum on duty cycle are assumed to
be E2=15[V] and Don=0.4.
ΔφV2＝E2×Don／ｆ[V×Sec]＝[Wb]
＝15×0.4/150000
＝40 [μWb]
When using a Mag-amp to also protect against over currents, Δφmag＝ΔφV2. Here, we assume that the
mag-amp only regulates voltage and set the incremental increase at the time of no current load as
KV=0.6.
Δφmag＝ΔφV2×KV＝40×0.6＝24 [μWb]
☆Choice of core size
The wire winding coefficient, Kf, is the coefficient that it is possible to wind on the inside of a toroidal
core. Usually, Kf=0.4 is used. The current density J is usually set as J=5～10[A/mm2]. Here, we assume
J＝8[A/mm2].
If the mag-amp's maximum operating temperature is assumed to be 120℃, we assume that the flux
density of the core decreases to 80%. We also allow flux design space to be 70%.
φ
C･AW ≧Δφmag×Io/(Kf×J)/Kt
≧24×10/(0.4×8)/(0.8×0.7)
≧133.9 [μWb・mm2]
From the standard specification table, MT12X8X4.5W is chosen.
☆Number of wire winding
N≧Δφmag/φCmin/Kt [turn]
≧24/6.31/(0.8×0.7)＝6.8
＝7 [turn]
☆Wire diameter
When the wire diameter is over φ1.0mm, there is difficulty in the actual wire winding of the toroidal cores.
Therefore, when the output current Io is over 5[A], parallel winding is used. Here, since Io＝10[A], two
parallel wires are used.
d＝2× Io/2/(π×J) [mm]
＝2× 10/2/(π×8)＝0.89 [mm]
As a result, 2 parallel φ0.9mm wires are wound.
☆Results of design (Operating Frequency 150kHz, 5V-10A, Voltage Regulation)
MT12X8X4.5W, φ0.9mm, 2 parallel windings, 7[turn]
Please always confirm operation on the actual circuit after design. Since the mag-amp is a passive part,
it becomes susceptible to effects from the waves of the transformer, and actual operating tests are
necessary.
Examples of the Design
Evaluation of the Mag-Amp Circuit Unit
Examples of the Design
Evaluation of the Mag-Amp Circuit Unit
Note) Operating flux is influenced by the main transformer of the circuit, and the value shown in the table is not necessarily applied as it is.
Design Example ( Forward Converter, 150kHz operating）
Voltage Control（at Kv=0.6）
3.3V
5V
12V
15V
24V
MT12S115
MT12S115
MT15S125
MT15S125
MT18S130
MT12S208
MT12S208
MT15S214
MT18S222
MT18S222
Current 15A
（φ0.9mm×3p.）
MT12 : 5turn
MT15 : 6turn
MT18S311
MT18 :14turn
MT21 :19turn
Over Current Protection (at E2×DON =1.2Vo）
MT12S115
MT12S115
MT15S125
MT18S130
MT21S134
10A
（φ0.9mm×2p.）
MT15:7turn
MT16:6turn
MT21:16turn
MT21:20turn
MS26:18turn
MT12S208
MT15S214
MT18S222
MT21S222
MT21:32turn
6A
(φ1.0mm)
10A
（φ0.9mm×2p.）
6A
(φ1.0mm)
15A
（φ0.9mm×3p.）
Reference
Reference
Voltage
Output Current vs. Transformer Voltage
1）At no-Load
Generally, the range of the flux becomes large at no, or small current load. There is a possibility that
the mag-amp may not be able to control the output voltage because there is a shortage of core flux.
This problem occurs because the large range of the flux density causes saturating on the other side
and there is not enough ability to control the voltage-time product. In order to set the allowances for
design, the wire winding for the Mag-amp is reduced and the operating range is confirmed.
However, the core flux necessary at the time of no current load is largely influenced by such factors as
the dummy current value. Therefore, when the core flux is large at no current load, such factors as the
dummy current value must be adjusted, taking efficiency into account.
2）At Full-Load
Generally, the mag-amp's flux range becomes small at the full current load. There is the possibility that
output voltage cannot be regulated because it is not possible to make the range any smaller. This
problem is called the dead angle.
The allowances for design at full current load are confirmed by increasing the number of wire windings.
However, the dead angle value is influenced not only by the core characteristics, but also by the
reverse recovery current of the output diode and leaked currents. Please select output diodes with fast
recovery times. Also, when using SBD (Schottky Barrier Diode), please use one with small current leaks
and stable temperature characteristics.
3）Temperature Rise
The temperature rise from no current load to full current load should be confirmed. Since the upper limit
temperature for continuous use of our mag-amp saturable cores is 120℃, the mag-amp should be
designed so that the sum of the surrounding temperature and core temperature rise does not exceed
120℃. Please measure core temperature rise under the condition of natural air-cooling (Without
cooling fan). Generally, the mag-amp is designed calculating the temperature rise at ΔT＝30℃～40℃.
With forward converters, the temperature rise at no current load is especially high. When this occurs,
the wire winding should be increased and the operating flux density reduced. When the temperature
rise is too high at full current load, the wire winding should be reduced and the operating magnetic field
reduced.
4）Output voltage precision
It is necessary to confirm the voltage regulation characteristics (specifications) from no current load
to full current load conditions. When there is a mismatch between the gain of the mag-amp and the
gain of the regulated circuit, the circuit vibrates abnormally. Especially when there are sounds from the
mag-amp circuit, there is a high possibility that the regulated circuit is abnormally vibrating.
5）Protection from Over currents
When protecting for over currents, the range of operating flux for the mag-amp becomes large. Please
set the maximum flux range to be 70% of the core flux, similar to when there is no current load.
V0
Transformer Voltage [ V ]
Output Current [ A ]
Transformer
No load
Mag-Amp controlled
Dead Angle (ΔVd)
− 22 −
Notices on Handle, Maintenance and Discontinue List
Discontinued List
Discontinued Type No. Substitution (recommend)
MB15X10X4.5 MS15X10X4.5W
MB18X12X4.5 MS18X12X4.5W
MB21X14X4.5 MS21X14X4.5W
MS8X7X4.5W (MS10X7X4.5W)
MS9X7X4.5W (MS10X7X4.5W)
MS10X6X4.5W (MS10X7X4.5W)
MT10X6.5W MT10X7X4.5W
SA4.5X4X3 AB5x4x3DY
SA5X4X3 AB5x4x3DY
SA7X6X4.5 (SS7X4X3W)
SA8X6X4.5 (SS10X7X4.5W)
SA10X6X4.5 (SS10X7X4.5W)
SA14X8X4.5 SS14X8X4.5W
Attention :
Same or similar core size items are listed up for substitution. Magnetic or electric characterisitcs are changeable.
Please test substitution parts before replacing to ensure performance.
Wired parts made by these cores are also discontinued items.
Discontinued Type No. Substitution (recommend)
FS10X4X1 (FS12X8X4.5W)
MA7X6X4.5X (MS10X7X4.5W)
MA8X6X4.5X (MS10X7X4.5W)
MA10X6X4.5X (MS10X7X4.5W)
MA14X8X4.5X MS14X8X4.5W
MA18X12X4.5X MS18X12X4.5W
MA22X14X4.5W (MS26X16X4.5W)
MA26X16X4.5W MS26X16X4.5W
MB8X7X4.5 (MS10X7X4.5W)
MB9X7X4.5 (MS10X7X4.5W)
MB10X7X4.5 MS10X7X4.5W
MB12X8X4.5 MS12X8X4.5W
MB14X8X4.5 MS14X8X4.5W
Notices of the amorphous magnetic parts on handle
Detail information are described on the technical data sheet or the specification for supply.
cross section
magnetic path length
μi
Bm
Br
-Hc Hc0
*1 Initial permeability is out of control in the case of saturable cores, because it is unrelated to the Mag-Amp.
Hm
Reference
Reference
Glossary of Amorphous Magnetic Parts
A magnetic core can be able to saturate. These cores have a high square shape
ratio, and it can use magnetic saturation and magnetic being un-saturated.
Magnetic core which has doughnut shape.
Effective core cross section area :Ae,
Ae [m2] = ((OD[m] - ID[m] ) x height HT[m] / 2 ) x pf
The ratio of the absolute area of magnetic material to its geometrical area .
Length of the magnetic circuit. In the case of the toroidal core, magnetic mean path
length Lm is adopted.
Lm [m] = (OD[m] + ID[m]) x π/2
Magnetic flux strength of the material, which is perpendicular magnetic flux of the
unit area.
B[T] = φ[Wb] / Ae [m2]
φ[Wb = V･sec] = B[T] x Ae [m2]
H[A/m] = I [A] / Lm [m]
μ = B / H. Inductance L is proportional to permeability μ.
First inclination of the initial growth of magnetic flux density B
（see the illustration below）
In this booklet, Bm is defined as the flux density at the magnetic field Hm.
（see the illustration below）
Br is the flux density at the time the magnetic field return to H = 0
（see the illustration below）
Total magnetic flux of the core. In this booklet, total magnetic flux φc is defined as
the following equation.
φc [Wb] = 2 x Bm [T] x Ae [m2]
The ratio of the Bm and Br. Greater the rectangular ratio, the more superior the
magnetic saturability.
Br / Bm = Br [T] / Bm [T]
Hc is the cross point of the BH curve and X axis. Smaller the Hc, the less the loss
and the more superior the Hc. （see the illustration below）
H
B
Maximum
Operating Temperature
Wire Winding
Mounting
Soldering
Circuit Design
Transport
and Storage
When soldering be sure that the core exterior will not be deformed by heat
conducted through the lead wire.
Do not subject parts to re-flow or flow soldering. (Except the surface mounting
type)
Be careful, of imput voltage, rated current, ambient temperature and temperature
rise.
When revising the circuit, please recheck the core temperature rise.
Recheck the maximum temperature or maximum loads.
Make sure not to apply any stresses which will lead to deformation of the core
exterior.
If the product is to be impregnated, bonded, cleaned or otherwise treated, confirm
that such treatment will not adversely affect the magnetic characteristics.
When impregnating the core, be sure that the magnetic properties will not be
influenced.
Prevent radiation and conduction from high temperature components from reaching
the core.
Be sure to consider vibration and shock when installing these parts.
Be careful at wire winding or lead insertion. Damage or deformation of the core or
insulating cover has a harmful influence.
Be careful to the rare short circuit.
120℃ (include temperature rising by self-heating, under natural air cooling)
(except FS series which is 85℃)
Do not drop the parts. Protect the parts from water.
Saturable Core
Toroidal Core
Cross Section
Packing Factor pf
Magnetic Path
Length Lm
Magnetic Flux
Density B
Magnetic Flux φ
Magnetic Field
Strength H
Permeability μ
Initial Permeability
μi
*
1
Maximum
Flux Density Bm
Residual Magnetic
Fux Density Br
Total Magnetic Flux
φc
Rectangular Ratio
Br / Bm
Coercive Force Hc
Technical Terms
− 23 −
Notices on Handle, Maintenance and Discontinue List
Discontinued List
Discontinued Type No. Substitution (recommend)
MB15X10X4.5
MB18X12X4.5
MB21X14X4.5
MS8X7X4.5W
MS9X7X4.5W
MS10X6X4.5W
MT10X6.5W
SA4.5X4X3
SA5X4X3
SA7X6X4.5
SA8X6X4.5
SA10X6X4.5
SA14X8X4.5
MS15X10X4.5W
MS18X12X4.5W
MS21X14X4.5W
(MS10X7X4.5W)
(MS10X7X4.5W)
(MS10X7X4.5W)
MT10X7X4.5W
AB5x4x3DY
AB5x4x3DY
(SS7X4X3W)
(SS10X7X4.5W)
(SS10X7X4.5W)
SS14X8X4.5W
Attention :
Same or similar core size items are listed up for substitution. Magnetic or electric characterisitcs are changeable.
Please test substitution parts before replacing to ensure performance.
Wired parts made by these cores are also discontinued items.
Discontinued Type No. Substitution (recommend)
FS10X4X1 (FS12X8X4.5W)
MA7X6X4.5X (MS10X7X4.5W)
MA8X6X4.5X (MS10X7X4.5W)
MA10X6X4.5X (MS10X7X4.5W)
MA14X8X4.5X MS14X8X4.5W
MA18X12X4.5X MS18X12X4.5W
MA22X14X4.5W (MS26X16X4.5W)
MA26X16X4.5W MS26X16X4.5W
MB8X7X4.5 (MS10X7X4.5W)
MB9X7X4.5 (MS10X7X4.5W)
MB10X7X4.5 MS10X7X4.5W
MB12X8X4.5 MS12X8X4.5W
MB14X8X4.5 MS14X8X4.5W
Notices of the amorphous magnetic parts on handle
Detail information are described on the technical data sheet or the specification for supply.
cross section
magnetic path length
μi
Bm
Br
-Hc Hc0
*1 Initial permeability is out of control in the case of saturable cores, because it is unrelated to the Mag-Amp.
Hm
Reference
Reference
Glossary of Amorphous Magnetic Parts
A magnetic core can be able to saturate. These cores have a high square shape
ratio, and it can use magnetic saturation and magnetic being un-saturated.
Magnetic core which has doughnut shape.
Effective core cross section area :Ae,
Ae [m2] = ((OD[m] - ID[m] ) x height HT[m] / 2 ) x pf
The ratio of the absolute area of magnetic material to its geometrical area .
Length of the magnetic circuit. In the case of the toroidal core, magnetic mean path
length Lm is adopted.
Lm [m] = (OD[m] + ID[m]) x π/2
Magnetic flux strength of the material, which is perpendicular magnetic flux of the
unit area.
B[T] = φ[Wb] / Ae [m2]
φ[Wb = V･sec] = B[T] x Ae [m2]
H[A/m] = I [A] / Lm [m]
μ = B / H. Inductance L is proportional to permeability μ.
First inclination of the initial growth of magnetic flux density B
（see the illustration below）
In this booklet, Bm is defined as the flux density at the magnetic field Hm.
（see the illustration below）
Br is the flux density at the time the magnetic field return to H = 0
（see the illustration below）
Total magnetic flux of the core. In this booklet, total magnetic flux φc is defined as
the following equation.
φc [Wb] = 2 x Bm [T] x Ae [m2]
The ratio of the Bm and Br. Greater the rectangular ratio, the more superior the
magnetic saturability.
Br / Bm = Br [T] / Bm [T]
Hc is the cross point of the BH curve and X axis. Smaller the Hc, the less the loss
and the more superior the Hc. （see the illustration below）
H
B
Maximum
Operating Temperature
Wire Winding
Mounting
Soldering
Circuit Design
Transport
and Storage
When soldering be sure that the core exterior will not be deformed by heat
conducted through the lead wire.
Do not subject parts to re-flow or flow soldering. (Except the surface mounting
type)
Be careful, of imput voltage, rated current, ambient temperature and temperature
rise.
When revising the circuit, please recheck the core temperature rise.
Recheck the maximum temperature or maximum loads.
Make sure not to apply any stresses which will lead to deformation of the core
exterior.
If the product is to be impregnated, bonded, cleaned or otherwise treated, confirm
that such treatment will not adversely affect the magnetic characteristics.
When impregnating the core, be sure that the magnetic properties will not be
influenced.
Prevent radiation and conduction from high temperature components from reaching
the core.
Be sure to consider vibration and shock when installing these parts.
Be careful at wire winding or lead insertion. Damage or deformation of the core or
insulating cover has a harmful influence.
Be careful to the rare short circuit.
120℃ (include temperature rising by self-heating, under natural air cooling)
(except FS series which is 85℃)
Do not drop the parts. Protect the parts from water.
Saturable Core
Toroidal Core
Cross Section
Packing Factor pf
Magnetic Path
Length Lm
Magnetic Flux
Density B
Magnetic Flux φ
Magnetic Field
Strength H
Permeability μ
Initial Permeability
μi
*
1
Maximum
Flux Density Bm
Residual Magnetic
Fux Density Br
Total Magnetic Flux
φc
Rectangular Ratio
Br / Bm
Coercive Force Hc
Technical Terms
AB3X2X6W AB3X2X3W 2pieces
Copyright 2015, TOSHIBA MATERIALS Co., LTD. All Rights Reserved Printed in Japan 27. 1. AT
