Soft Ferrites TPC

Soft Ferrites
Applications
High Power
TPC
SMPS
Lighting
TV & Monitors
Filtering
9
Soft Ferrites
Applications
Shapes of magnetic cores depend on applications:
• E cores and RM cores:
They are used in computer, radio communication, interference suppression, SMPS for wide-band transformers,
power transformers, pulse transformers.
• U cores:
They are used in TV applications, industrial and professional applications for wide-band transformers and high
voltage transformer.
Soft ferrite cores are used in a large band of applications,
with different shapes and adapted materials. Today the main
application areas are:
■ Power Application
■ Filtering Application
APPLICATIONS
ADVANTAGES
DRAWBACKS
Low power range (200W) Simples topology - low cost Poor current form factor
Output current < 10A
Multi-output capability
Max operating frequency:
80kHz
Typ. efficiency: 65 to 80%
B - FORWARD CONVERTERS
HOW DOES IT WORK?
I1
D1
T
L
D2
C
V2
V1
TR
D3
I. POWER APPLICATION
• High Power
During “TR” on: “D1” is opened and the primary energy
is directly transferred to the secondary through the transformer “T” and stored in choke “L”.
During “TR” off: “D2” is opened and energy stored in “L”
is returned to load.
Remark: an important airgap is needed in the choke but
low or no airgap is required in the transformer (low magnetizing energy returned to the input by the way of the
auxiliary winding and “D3”).
A power transformer transmits energy, transforms voltage to the required level and provides galvanic separation. It operates under conditions which require special
power ferrites with low losses and high saturation levels.
• SMPS
The following table summarize the structures of a SMPS
circuit.
Three principle structures of a switched mode power supply
circuits are:
A - Flyback Converters
B - Forward Converters
C - Push-Pull Converters
APPLICATIONS
ADVANTAGES
Power range typ.:100 to
Low ripple output (built in
300W output current > 7A filter LC)
DRAWBACKS
Not optimized for
multi-outputs
High frequency capability
High efficiency: up to 90%
A - FLYBACK CONVERTERS
In a flyback converter, all the energy to be transferred to
the output capacitor and load is, at first, stored in the
inductor.
HOW DOES IT WORK?
I1
T
D
C - PUSH-PULL CONVERTERS
The push-pull converter is an arrangement of two forward converters operating in antiphase. For the same
operating conditions and power throughput, its design
can use a smaller transformer core.
• Ballast
C
Ballast are used for fluorescent lamps. It limits the current
and works like coil. Ballast resistance is calculated to
obtain the arc voltage of the lamp and the right current to
run with right conditions.
For the best efficiency, dimensional and electromagnetic
parameters of ferrite cores transmit the exact value of
cathode current, lamp voltage and lamp current.
V2
V1
TR
During “TR” on: “D” is blocked and primary energy is
stored in the transformer “T”.
During “TR” off: “D” is opened and energy is returned to
the load.
Remark: an important airgap is needed in the magnetic
circuit in order to prevent saturation.
10
TPC
Inductor L
Ballast
Starter
220
50Hz
Tube
C
Soft Ferrites
Applications
II. FILTERING APPLICATION
High permeability materials represent soft ferrites used in
the filtering application like EMI suppression, telecommunication, tuning, etc...
To avoid this problem, inductive components are very
effective, especially at high frequency. With high permeability material, inductors has high impedance for the
interfering unwanted signal.
• Telecommunication
• EMI Suppression
Electronic equipment development pollutes the environment of electromagnetic waves. For the best working of
devices, laws will become more stringent in the near future.
Most important applications in telecommunication, are filter
coils and “pulse and signal transformer”. For those applications, a high quality factor (Q) is needed. Good wideband
characteristics transmit analog signals or digital pulses
without much distortion.
III. FERRINOX MATERIAL: QUICK SELECTION GUIDE
A complete description of power ferrite materials is presented pages 18 to 34.
The following table summarize the typical applications.
MATERIAL FOR POWER APPLICATIONS
MATERIAL
MAIN FEATURES
APPLICATION
CORE TYPE
B2
Low losses for low frequency
(25 to 150 kHz)
Power transformers
DC/DC converters
E, U Cores and
Toroids
F1
Very low losses for medium frequency
(50 to 250 kHz)
and high flux density
Power transformers
DC/DC converters
E, U, PQ, EP and RM
Cores, Toroids
F2
Very low losses for high frequency
(100 to 500 kHz)
Power transformers
DC/DC converters
E, U, RM and Planar
Cores
F4
Very low losses for high frequency
(500 to 1.5 MHz)
Power transformers
DC/DC converters
E and Planar Cores
MATERIAL FOR TV TRANSFORMERS AND FLYBACK TRANSFORMERS
MATERIAL
MAIN FEATURES
APPLICATION
CORE TYPE
B3
High flux density and negative
power loss temperature slope
at high temperature
Noise suppression
Chokes
Broadband transformers
Drivers
Small
E and U
Cores
B5
High flux density and low
losses at high temperature
(32 kHz)
General purpose power
Transformers
Drivers
E and U Cores
Toroids
TPC
11
Soft Ferrites
Applications
IV. DC BIAS CORE SELECTION CURVES
LI2 VS AL
To prevent saturation of the magnetic circuit in a choke,
the following curves provide the AL limit before saturation
of most E, U, RM and FM cores (corresponding to a 20%
inductance drop) at 25°C and 100°C operating temperatures.
• Draw a horizontal line at the Y axis coordinate corresponding to the required LI2 max value:
L
: Inductance required (mH)
Imax : Peak current
• Any core whose line intersects with this horizontal line
may be used.
• Draw a vertical line at this intersection to get the AL
value.
In the same way, the following curves provide the maximum
applicable ampere turns on a core before saturation:
• Draw a vertical line at the X axis coordinate corresponding to the required AL value
12
• The intersection with the LI2 line of the required core indicates NI max value by calculating:
NI max = √(LI2 / AL)
Notes:
1. These graphs are valid for B1, B2, F1.
2. Increase by about 10% the LI2 max value for B3, B5.
3. The lower and upper core limits correspond to the
optimum effective permeability range: 54 ≤ µe ≤ 300.
V. DC BIASED INDUCTANCE
• AL versus N x IS curves are given for the following cores
in the U-core section:
UR3513B - UR3513D - UR3513H - UR3915A
UR4014A - UR4022A - UR4316A - UR4916A
Note: These graphs are valid with a specific coil for each
core only.
TPC
Soft Ferrites
Applications
(please see the respective curves at the end of this section)
AL CURVES E CORES
AL CURVES E CORES
10
10
E-2206A
E-2005B
E-2206A
LI2 (mJ) at 100°C
LI2 (mJ) at 25°C
E-2005B
1
E-2006A
E-1907A
E-1905A
E-1605A E-1605B
E-1306A
0.1
1
E-2006A
E-1907A
E-1905A
E-1605A E-1605B
E-1306A
E-1304A
0.1
E-1304A
0.01
10
100
0.01
10
1000
100
AL (nH)
Figure 1
Figure 2
AL CURVES E CORES
AL CURVES E CORES
100
100
E-4012A
E-3509A
E-3510A E-3510B
LI2 (mJ) at 100°C
LI2 (mJ) at 25°C
E-4012A
10
1000
AL (nH)
E-2507A
E-4113A
E-3213A E-3313A
E-3611A
E-3007B E-3008A
1
10
E-3509A
E-3510A E-3510B
E-2507A
E-4113A
E-3213A E-3313A
E-3611A
E-3007B E-3008A
1
E-2506A E-2506B
E-2506C E-2507B
0.1
10
100
E-2506A E-2506B
E-2506C E-2507B
0.1
10
1000
100
Figure 3
Figure 4
AL CURVES E CORES
AL CURVES E CORES
1000
1000
LI2 (mJ) at 100°C
LI2 (mJ) at 25°C
1000
AL (nH)
AL (nH)
E-6527A
100
E-5521A
E-4220A E-4220B
E-7032A
E-5525A
10
100
E-6527A
E-5521A
E-4220A E-4220B
E-7032A
10
E-5525A
E-4916A
E-4916A
E-4215A E-4215B
E-4215A E-4215B
1
10
100
1
10
1000
AL (nH)
100
1000
AL (nH)
Figure 5
Figure 6
TPC
13
Soft Ferrites
Applications
AL CURVES EI CORES
AL CURVES EI CORES
100
100
EI4012A
10
EI3011B
EI2506C
EI4215B
EI3313A
1
EI4012A
LI2 (mJ) at 100°C
LI2 (mJ) at 25°C
EI3510B
10
EI3510B
EI3011B
EI2506C
EI4215B
1
EI3313A
EI2206A
EI2206A
0.1
10
100
0.1
10
1000
100
AL (nH)
1000
AL (nH)
Figure 7
Figure 8
AL CURVES EC CORES
AL CURVES EC CORES
100
100
EC7017A
EC7017A
EC5214A
EC5214A
10
LI2 (mJ) at 100°C
LI2 (mJ) at 25°C
EC4112A
EC3510A
1
EC4112A
10
EC3510A
1
0.1
10
100
0.1
10
1000
100
1000
AL (nH)
AL (nH)
Figure 9
Figure 10
AL CURVES ET CORES
AL CURVES ET CORES
100
100
ET5419A
ET5419A
ET4916A
ET4415A
ET4916A
ET4415A
LI2 (mJ) at 100°C
LI2 (mJ) at 25°C
ET3913A
10
ET3411A
ET2910A
100
0.1
10
1000
100
1000
AL (nH)
AL (nH)
Figure 11
14
ET3411A
ET2910A
1
1
0.1
10
ET3913A
10
Figure 12
TPC
Soft Ferrites
Applications
AL CURVES ER CORES
AL CURVES ER CORES
AL CURVES RM - FM CORES
FM8770A
100
100
100
FM5039A
ER4518B
ER5519A ER5519B
ER4518B
ER5519A ER5519B
RM1400B
ER4821A
ER5318A
ER4518A ER5221A
ER4013A
ER3411A
1
ER3913A ER3913D
10
ER2811A
ER4821A
ER5318A
ER4518A ER5221A
ER4013A
ER3411A
1
0.1
10
100
10
RM1000B
RM0800B
RM0600B
1
0.1
10
1000
LI2 (mJ) at 25°C
10
ER2811A
LI2 (mJ) at 100°C
LI2 (mJ) at 25°C
ER3913A ER3913D
100
AL (nH)
RM0500B
0.1
10
1000
100
AL (nH)
Figure 13
Figure 14
AL CURVES RM - FM CORES
1000
AL (nH)
Figure 15
AL CURVES U CORES
AL CURVES U CORES
FM8770A
100
100
100
RM1000B
RM0800B
10
U-3126A
RM0600B
U-2513A
U-1204A
1
1
RM0500B
U-2007A U-2507A
LI2 (mJ) at 100°C
(mJ) at 25°C
RM1400B
10
LI2
LI2 (mJ) at 100°C
FM5039A
10
U-3126A
U-2513A
U-1204A
1
U-2007A U-2507A
U-1105A
U-1506A U-1706A
U-1105A
U-1506A U-1706A
U-1606A
U-1606A
0.1
10
100
0.1
10
1000
100
AL (nH)
Figure 16
Figure 17
AL CURVES U CORES
AL CURVES U CORES
100
1000
Figure 18
1000
U--141B
U-9330A IU9330A
100
U--102A IU-102A
U-4628A
10
LI2 (mJ) at 100°C
U--141A
U-9320A IU9320A
U--126A IU-126A
U-9316A IU9316A
LI2 (mJ) at 25°C
0.1
10
AL (nH)
AL (nH)
1000
1
10
1000
U--141A
U-9320A IU9320A
U--126A IU-126A
U-9316A IU9316A
100
U--141B
U-9330A IU9330A
U--102A IU-102A
U-4628A
10
100
1000
AL (nH)
Figure 19
1
10
100
1000
AL (nH)
Figure 20
TPC
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