The KEMET TPI ferrite core inductors are designed for a very low core loss. Its’ flat wire, “1 turn through the construction” design, enables high efficiency at large currents. The core material used is ideal for high switching frequency applications. TPI power inductors can be used up to 125°C ambient temperature as a resonant inductor in LLC converter applications or for EMI reduction on processor boards up to 50A.

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TPI Power
Inductor Webinar
April 2019

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TPI Power Inductor Webinar
• Inductor basics
• Behavior of different soft magnetic material
• Component mechanical layout
• Applications (DC Optimization Inductor & AC Optimization Inductor)
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What Is an Inductor?
Coil
(Wire)
Core
Material
Magnetic
Field
Current through the copper
coil creates a magnetic field
and stores it.
Core
Material
Different core materials change
magnetic field strength.
Air
(None)
Ferrite
(Iron)
Metal
Composite
i
dφ
dt
e
Magnetic flux φ
The coil converts
electric energy into magnetic energy
and stores it.
e = -
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⊿Ipp[A]
Frequency (time)
Voltage[V]/Current[A]
0
Voltage and Current image DC/DC converter output
Iout[A]
DCcurrent[A]
1
2
W = x L x i 2 [J]Magnetic energy in an inductor :
Fundamentals

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Iron Loss Core Loss
Copper Loss Skin Effect
Proximity Effect
Conductor
Thickness
Material
Composition
AC Loss across an Inductor
Conductor
Distance
Eddy Current
Pcv = Ph + Pe
Composition and Structure
Adjust the thickness / shape
according to frequency.
Affects Lorentz Force
Smallest at 1T Conductor
Avoid crossing magnetic
flux to the conductor.
Clearance
TPI inductor do not use a coil,
proximity effect is very small.
The conductor is just straight.
Just focus on the Skin Effect and
the Eddy Current impact.
Skin Effect Proximity Effect Eddy Current
Conductor
Magnetic Flux
Eddy Current
-8
-6
-4
-2
0
2
4
6
8
-60
-40
-20
0
20
40
60
I nominal V
Current[A]
Voltage[V]
Current Wave Form
F = 300kHz
Reduce ACR for Current
Flinging Loss
Cross section image
Current
Current density : High
Current density : Low
Breakdown of AC Loss
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Ferrite Inductor or Metal Composite
Inductor?
Material Type
Ferrite Inductor Metal Inductor
Ni-Zn Mn-Zn Fe Based
Inductance Fair Very Good Not Good
Magnetic Saturation Fair Not Good Very Good
Thermal Property Fair Not Good Very Good
Efficiency Fair Very Good Fair
Resistance of Core Very Good Not Good Fair
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1. Higher inductance with high permeability
2. Stable inductance in the right range
Advantage of Ferrite
1. Very slow saturation
2. Very stable saturation with heat rise
Advantage of Metal Composite
Metal CoreMn-Zn Ferrite
Core Loss Comparison
Very low core loss in dynamic frequency range
Advantage of Ferrite
High L and Low DCR capability
Good for Auto app especially
Low power consumption capability
Ferrite and Metal Composite Comparison
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• lower DCR
• lower core loss
Conductor
& Terminals
GAP
Mn-Zn Core
Mn-Zn Core
The lower DCR
Advantage of assembled ferrite
Inductor Structure
TPI Series - Assembled Ferrite
TPI
Ferrite core
(Mn-Zn)
Flat wire
(Direct terminal)
Assembled
• Lowest DCR
• Lowest core
loss
Large load
convertor
(CPU, GPU,
Mem)
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• TDP << Pmax(90A)
• Fs : 1~3 MHz
• Light load efficiency
• Shrinking : L x W
• The lower core loss material
for low power consumption
• Small footprint
for low power loss on load
Ferrite type
When to Choose Ferrite Inductor ?
TPI series NA FP series PA series NA NA SRC series HCB series NA NA
9

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12V Power Distribution
Conventional Circuit
PSU
With STC
48V Power Distribution 1V12V
CPU
1V
DC/DC Convertor
DC/DC ConvertorSTC
(Switched tank convertor)
Soft SW topology
Hard SW Topology
High loss on the load line
Hard SW Topology
Efficient and scalable
(Switched tank convertor)
AC Optimization Inductor DC Optimization Inductor
2nd stage
1ST stage
Improve power loss on the line
to 1/16 by 48V power distribution
Power Conversion for CPU example
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For Whiley, v.Purley
The current for an inductor
456A(Imax) / 7p = 65A for ´X´ μsec at 125C
FET&IC
Need to reduce
this distance
between CPU and
Inductors
Peak power is going up and number of DC/DC
convertor increase. Reducing product width and put
inductors closer to CPU as possible to improve the
loss on the line.
Current Shape
Size:11x8x8.2mm Size:11x6.0x10mm
Saving Footprint
Size:10x6.5x9mm
Horizontal type
Vertical type
Can be the option
for low height
More
Narrow
width
required
CPU
The space for Inductor
P = I2 x R (≒Distance)
DC Optimization Inductor
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Generation Purley Whiley, v.Purley Eagle Stream
Material GEN
Suitable Freq. [kHz] 600~800 800~1500 1500~3000
Core Loss [mW/cc] 24 < 10 < 10
Permeability 2300 1000 ≒1000
Magnetic flux density 520 480 < 480
Current Fe B45 NEW
Current
B45
f x B = 12500
NEW
Material : B45
L : 10.0mm
W : 6.0mm
H : 9.0mm
L [nH] DCR [mΩ] Isat [A]
Target 70 - >120
Proposal 70 0.185 124
Engineering Sample： Available
For Eagle Stream
DC Optimization Inductor
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Model
L [nH]
@100kHz, 0.1Vrms
DCR [mΩ]
at 25˚C
Rated Current [A] (Reference)
Temperature
Rated Current
[A]
Isat1
at 25˚C
Isat2
at 85˚C
Isat3
at 125˚C
TPI118082L150N 150 +/- 10% 0.29 +/-5% 93 79 67 50
TPI118082L180N 180 +/- 10% 0.29 +/-5% 79 67 57 50
TPI128080L180N 180 +/- 10% 0.29 +/-5% 78 68 54 52
TPI128080L210N 210 +/- 10% 0.29 +/-5% 70 60 52 52
TPI128080L230N 230 +/- 10% 0.29 +/-5% 64 56 50 52
DC optimization type
Narrow
Width
Under
DevelopmentTPI106090L070N 70 +/- 10% 0.185 +/- 5% 162 134 114 56
Expand Lineup
Low
Height
TPI Series Line-up
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35Ao-p, 300kHz
The Core Loss is
improved with the suitable
material for STC topology.
The Flinging Loss is
improved by the
optimization of product
shape.
-55%
Material Product shape
STC utilizes series resonant with MLCC
Total Loss Comparison
14
Total Loss Comparison

15. © KEMET Electronics. All Rights Reserved. Required low core loss for a wider range of the Magnetic Flux Density.
Hard SW
Ferrite core for conventional hard switching
Material Selection for Core Loss
15
-55%

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TPI078060L047N
TPI078060L056N
TPI078060L068N
TPI078060L082N
Inductor
AC Optimization
Inductor
To construct LC resonant circuit for STC topology.
KEMET provides the full solution with Inductor and MLCC.
L7 x W8 x H6 mm
Total Solution for STC Topology
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0
20
40
60
80
100
0 20 40 60 80 100
INDUCTANCE[NH]
DC_CURRENT [A]
0
20
40
60
80
100
0 20 40 60 80
DC_CURRENT [A]
25℃ 60℃ 100℃
0
20
40
60
80
100
0 20 40 60 80 100
DC_CURRENT [A]
0
20
40
60
80
100
0 20 40 60 80
DC_CURRENT [A]
Saturation Characteristic (Reference):
RoHS Compliant Halogen Free
TPI078060L047N TPI078060L056N TPI078060L068N TPI078060L082N
Model
L [nH]
@100kHz, 0.1Vrms
DCR [mΩ]
at 25˚C
Rated Current [A] (Reference)
Rated Current
[A]Isat1
at 25˚C
Isat2
at 60˚C
Isat3
at 100˚C
TPI078060L047N 47 +/- 10% 0.31 +/- 10% 90 83 73 53
TPI078060L056N 56 +/- 10% 0.31 +/- 10% 81 74 64 53
TPI078060L068N 68 +/- 10% 0.31 +/- 10% 69 63 55 53
TPI078060L082N 82 +/- 10% 0.31 +/- 10% 54 51 43 53
TPI Series next Line-up
AC Optimization Type
17

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More new magnetic products
18
Metal composite
SMD power inductor
Wireless power transfer
soft and hard material
High frequency
absorber material
Flexsuppressor®
Automotive high voltage
DC common mode chokes

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Thank you