EMI Core and Flex Suppressor - ec.kemet.com · © 2019 KEMET Corporation EMI Core and Flex Suppressor® Design and Characteristics

© 2019 KEMET Corporation

EMI Core and Flex Suppressor®

Design and Characteristics


EMI Cores, Chokes, and Flex Suppressor®

Flex Suppressor®EMI Cores Chokes


Electromagnetic InterferenceRadiated vs. Conducted

Source Target

Radiated

Conducted


Chokes



Hard and Soft Magnetic Material

Magnetization of Magnetic Material

The magnetic material is magnetized by the magnetic

field generated by coils.

Hard Magnetic MaterialMagnetization remains even if the energization by the coils is cut off.

Soft Magnetic MaterialMagnetic flux is lost when energization stops.

A soft magnetic material has an impedance for each frequency.Noise could be suppressed by impedance.

This is a permanent magnet.

Current

Magnetic Material

Iron Powder


Normal & Common Mode Chokes

Normal Mode Choke Coil Common Mode Choke Coil

• Normal current flows to the coil, then magnetic flux occurs in the coil.

• The magnetic flux creates an impedance, and the electromagnetic noise is attenuated by the impedance.

• Since the signal current is normal current, the magnetic flux is cancelled by each coil, and the impedance is not active.

• Common current flows to both coils, then the magnetic flux occurs in the same direction increasing the impedance.


Improved

Material

SCRL series

SSRL series

SCR series

Large SCR series

Low

Profile Low

Loss

IMP

ED

AN

CE

[oh

ms]

PE

RM

EA

BIL

ITY

Performance

Small

Size SSR series


Duel Mode Choke Coil

3 in 1＋

Common Mode Choke Differential Mode

Choke x 2Dual Mode Choke

Conventional Design New Design

Reduce Footprint

& Save Space


EMI Cores



30 100050 100 5000

70

10

20

30

40

50

60

周波数

レベル

[MHz]

[dB(μV/m)]

Frequency

Rad

iati

on

No

ise

dB

(μV

/m)

Before Filtering

30 100050 100 5000

70

10

20

30

40

50

60

周波数

レベル

[MHz]

[dB(μV/m)]

Frequency

Rad

iati

on

No

ise

dB

(μV

/m) CISPR14

Class A Limit

CISPR14

Class B Limit

After Filtering

EMI FilteringEffect of Using EMI Suppression

An EMI core is a passive electric component used to suppress high frequency noise generated in electronic circuits.

http://en.wikipedia.org/wiki/Electronic_noise


EMI CoresTypes of Cores

Solid Snap-On “Snail-Shaped”

• Manganese Zinc (MnZn) for AM band range

• Nickel-Zinc (NiZn) for FM band range

• More than 100 types of variations available

EMI Cores suppress high frequency noise

by increasing impedance obtained by ferrite core.

Cables connected to devices act as an antenna to radiate the noise.


EMI CoreDefining Parameters

• Round or flat cable

• Mounting versions

• Shape and dimension

• Diagram shows impedance over frequency

• Impedance increases by squaring the

number of turns


EMI CoreFrequency Range

Depends on the material:


Flex Suppressor®



Electromagnetic InterferenceRadiated vs. Conducted

Source Target

Radiated

Conducted


Flex Suppressor® SheetsOverview

What is it?

• A flexible, polymer sheet with micro-magnetic foils

• Shields the “outside” against high frequency radiation

• Shields the “inside” against outside influences or in dense designs the interference between devices

How does it work?

• The sheet absorbs the electromagnetic noise

• Converts them into heat

Benefits

✓ Self adhesive or blank backside

✓ Range of temperature -40°C up to +105°C

✓ 25µm to 0.5 mm thick

✓ Relative permeability from 25 to 160

✓ Flame retardant versions (UL94 V-0 certified)

✓ Reflow capable (use with specific adhesive tape)


Flex Suppressor®

Permeability

• High Permeability (µ) =

Strong Magnetic Field Concentration

• High µ Materials Absorb EMI

• High µ Absorb and Re-shape Magnetic Fields

µ` = Inductance

µ`` = Resistance (loss)


0

1

2

3

4

5

6

0 2 4 6

Att

en

uati

on

[d

B]

Frequency [GHz]

FX Type

FF Type

FG Typewith Highest Permeability

with UL94V-0

For GHz

Decoupling Characteristics

FX

FF

High

4dB/div. total 60dB

Simulation(HFSS)

Transmitter Receiver

• With metal

• With metal and Flex Suppressor (FS)

Low

Metal

Metal

FS

• Free space

FG

LTE Band

700-960MHz

Metal

Flex Suppressor

(t:100μm)

Wi-Fi Band

2.4-5GHz

New Material

Underdevelopment

Flex Suppressor®

Material Selection

Measurement Method

Magnetic Field Strength

0

2

4

6

8

10

12

14

16

50 100 150 200 250 300 350

Thickness (μm)

0

1

2

3

4

5

0 25 50 75 100

Att

en

ua

tio

n (

dB

) @

70

0M

Hz

0

20

40

60

80

100

120

140

160

1 10 100 1000 10000

Pe

rme

ab

ilit

y

Frequency [MHz]

Outline

Decoupling @700MHz

Specifications

Type FF1 EFF4

Operating temperature -40 ~ 105℃

Thickness (mm) 0.050 0.1, 0.2, 0.3, 0.5

Standard form

Standard dimensions

Roll

240㎜ x 50m(Typ.)

Sheet

240㎜ x 240㎜(Typ.)

Specific gravity (23℃) 3.0 (typ.) 3.7 (typ.)

Tensile strength (MPa) 5.0 6.9

Surface resistivity (Ω/□) 1.0×106 (typ.)

Environment RoHS Compliant

Halogen Free

Flame retardant UL94V-0(No.E176124)

Relative permeability 3MHz 100 (typ.) 140 (typ.)

Permeability Characteristics

FF1(50)

EFF4(01)

EFF4(02)

EFF4(03)

EFF4

FF1 μr’

μr”

Core:6inch

Above specifications are for FLEX SUPPRESSOR® alone.

• UL94-V0 type

• Low environmental impact, Halogen free

• Reflowable (260˚C)*Please use double-sided adhesive tape with reflowable grade

FF TypeFF1 & EFF4 (UL94V-0)

0

1

2

3

4

5

0 25 50 75 100

Att

en

ua

tio

n (

dB

) @

70

0M

Hz

0

20

40

60

80

100

120

140

160

180

1 10 100 1000 10000

Pe

rme

ab

ility

Frequency [MHz]

0

2

4

6

8

10

12

14

16

50 100 150 200 250 300 350

Thickness (μm)

Outline

Decoupling @700MHz

Specifications


FX5(25)

FX5(50)

FX5(75)

μr’

μr”

• High permeability type

• Low environmental impact, Halogen free and

Red phosphorus free


EFX6(01)

EFX6(02)

EFX6(03

)

EFX6FX5

Type FX5 EFX6


Thickness (mm) 0.025, 0.050, 0.075 0.1, 0.2, 0.3

Standard form

Standard dimensions

Roll

240㎜ x 50m(Typ.)

Sheet

240㎜ x 240㎜(Typ.)




Environment

RoHS Compliant

Halogen Free

Red

phosphorous

Free

Flame retardant UL94 HB(No.E176124)

Relative permeability 3MHz 150 (typ.) 160 (typ.)

Core:6inch


FX TypeFX5 & EFX6 (High μ)

0

2

4

6

8

10

50 100 150 200 250 300 350

Thickness (μm)

0.0

0.5

1.0

1.5

2.0

0 25 50 75 100

Att

en

uati

on

(d

B)

@2

.4G

Hz

Outline

• High frequency type (for Wi-Fi, etc.)

• Low environmental impact, Halogen free and

Red phosphorus free


Decoupling @2.4GHz

Specifications


FG1(25)

FG1(50)

FG1(75)

EFG2(01)

EFG2(02)

EFG2(03)

0

5

10

15

20

25

30

35

40

45

50

1 10 100 1000 10000

Pe

rme

ab

ility

Frequency [MHz]

μr’

μr”

EFG2

FG1

Type FG1 EFG2


Thickness (mm) 0.025, 0.050, 0.075 0.1, 0.2, 0.3

Standard form

Standard dimensions

Roll

240㎜ x 50m(Typ.)

Sheet

240㎜ x 240㎜(Typ.)




Environment

RoHS Compliant

Halogen Free

Red phosphorous Free

Flame retardant UL94 HB(No.E176124)

Relative permeability 3MHz 25 (typ.) 35(typ.)

Core:6inch


FG TypeFG1 & EFG2 (GHz)


NFC (RFID etc)Radiation (for EMI regulation)

For RFID

For Wireless Charging

For EMI

Flex-suppressor

Suppression of radiated noise

from CPU/GPU, signal line,

cable, etc.

For De-sense

Wi-Fi for internal interference

LSI

Noise

LCD

Antenna

Coaxial cable

RF unit

Flex-suppressor

Internal noise is interfering to

Wi-Fi receiving sensitivity.

Flex-suppressor improves de-

sense.

For ESD

ESD

Internal interference caused by

ESD is a factor of false operation.

Flex-suppressor improves this

issue.

LSI

CurrentFlux

ESD

Flex-suppressor

Metal

Case

Main board (metal)

IC Card

Flux Loop

antenna

IC Card

Flex-suppressor

Up

NFC communication distance is

enhanced by Flex-suppressor.

Wireless charging

Conversion efficiency is improved

by using Flex-suppressor.

Tx coilRx coil

Spreading Flux

Flex-suppressor

Gathering Flux by

Flex-suppressor

Magnetic ShieldingAbsorption

Flex Suppressor®

Applications


Sheet

240mm x 240mm

Roll

240mm x 50m

Reel (for cable)

5mm x 1000m

Flex Suppressor®

Product Forms


Type Form Current NEW

General

240mm x 240mm

Sheet EFX EFX6

240mm x 50m

Roll FX2 FX5

UL 94-V0

240mm x 240mm

Sheet EFF EFF4

240mm x 50m

Roll FF1

GHz

240mm x 240mm

Sheet EFG EFG2

240mm x 50m

Roll FG1

NFC

220mm x 185mm

Sheet RM4A

240mm x 50m

Roll M4

Flex Suppressor®

Lineups


Best Solution for RF Noise

EMI

Radio

Desense ESD

Global Share No.1Thin & Flexible

Wireless

Power

Transfer

RFID


Thank You!

Documents

EMI Core and Flex Suppressor - ec.kemet.com · © 2019 KEMET Corporation EMI Core and Flex Suppressor® Design and Characteristics