Data SheetData Sheet
Date: June 2013
EPCOS AG 2013. Reproduction, publication and dissemination of this data sheet and the
information contained therein without EPCOS’ prior express consent is prohibited.
Ferrites and accessories
E 8.8
Core and accessories
Series/Type: B66302
206/13
Please read Cautions and warnings and
Important notes at the end of this document.
■To IEC 61246
■For miniature transformers, e.g. DC/DC
converters for surface mounting
■Available with SMD coil former
■Delivery mode: single units
Magnetic characteristics (per set)
l/A = 3.1 mm–1
le= 15.5 mm
Ae= 5 mm2
Amin = 3.6 mm2
Ve= 78 mm3
Approx. weight 0.50 g/set
Ungapped
Material AL value
nH
ePV
W/set
Ordering code
N30 1000 +30/–20% 2460 B66302G0000X130
T38 2100 +40/–30% 5170 B66302G0000X138
N87 550 +30/–20% 1350 < 0.035 (200 mT, 100 kHz, 100 °C) B66302G0000X187
B66302Core
E8.8
306/13
Please read Cautions and warnings and
Important notes at the end of this document.
SMD coil former with gullwing terminals
Material: GFR liquid crystal polymer (UL 94 V-0, insulation class to IEC 60085:
F max. operating temperature 155 °C), color code black
Vectra E 130i E106764 (M), POLYPLASTICS CO LTD
Vectra E 130i E83005 (M), TICONA
Solderability: to IEC 60068-2-58, test Td, method 6 (Group 3): 245 °C, 3 s
Resistance to soldering heat: to IEC 60068-2-58, test Td, method 6 (Group 3): 255 °C, 10 s
permissible soldering temperature for wire-wrap connection on coil former: 400 °C, 1 s
Winding: see Data Book 2013, chapter “Processing notes, 2.1”
Plastic cover cap
Used to protect the transformer against external influences, for stamping and for improved process-
ing on assembly machines
Material: GFR polyamide (UL 94 V-0, insulation class to IEC 60085:
F max. operating temperature 155 °C), color code white
Stanyl TW250F6 E47960 (M), DSM ENGINEERING PLASTICS B V
Coil former Plastic cover cap
Sections AN
mm2
lN
mm
AR value
Terminals Ordering code
1 2.7 14.9 190 8 B66302D1008T001
2 1.7 14.9 302 8 B66302D1008T002
Plastic cover cap B66302A2000X000
B66302Accessories
E8.8
406/13
Mechanical stress and mounting
Ferrite cores have to meet mechanical requirements during assembling and for a growing number
of applications. Since ferrites are ceramic materials one has to be aware of the special behavior
under mechanical load.
As valid for any ceramic material, ferrite cores are brittle and sensitive to any shock, fast changing
or tensile load. Especially high cooling rates under ultrasonic cleaning and high static or cyclic loads
can cause cracks or failure of the ferrite cores.
For detailed information see chapter “Definitions”, section 8.1.
Effects of core combination on AL value
Stresses in the core affect not only the mechanical but also the magnetic properties. It is apparent
that the initial permeability is dependent on the stress state of the core. The higher the stresses are
in the core, the lower is the value for the initial permeability. Thus the embedding medium should
have the greatest possible elasticity.
For detailed information see chapter “Definitions”, section 8.2.
Heating up
Ferrites can run hot during operation at higher flux densities and higher frequencies.
NiZn-materials
The magnetic properties of NiZn-materials can change irreversible in high magnetic fields.
Processing notes
– The start of the winding process should be soft. Else the flanges may be destroid.
– To strong winding forces may blast the flanges or squeeze the tube that the cores can no more
be mount.
– To long soldering time at high temperature (>300 °C) may effect coplanarity or pin arrangement.
– Not following the processing notes for soldering of the J-leg terminals may cause solderability
problems at the transformer because of pollution with Sn oxyd of the tin bath or burned insulation
of the wire. For detailed information see chapter “Processing notes”, section 8.2.
– The dimensions of the hole arrangement have fixed values and should be understood as
a recommendation for drilling the printed circuit board. For dimensioning the pins, the group
of holes can only be seen under certain conditions, as they fit into the given hole arrangement.
To avoid problems when mounting the transformer, the manufacturing tolerances for positioning
the customers’ drilling process must be considered by increasing the hole diameter.
Cautions and warnings
Ferrites and accessories
Cautions and warnings
506/13
Symbol Meaning Unit
A
Ae
AL
AL1
Amin
AN
AR
B
B
B
ˆ
B
ˆ
BDC
BR
BS
C0
CDF
DF
d
Ea
f
fcutoff
fmax
fmin
fr
fCu
g
H
H
ˆ
HDC
Hc
h
h/i2
I
IDC
I
ˆ
J
k
k3
k3c
L
Cross section of coil
Effective magnetic cross section
Inductance factor; AL = L/N2
Minimum inductance at defined high saturation ( a)
Minimum core cross section
Winding cross section
Resistance factor; AR = RCu/N2
RMS value of magnetic flux density
Flux density deviation
Peak value of magnetic flux density
Peak value of flux density deviation
DC magnetic flux density
Remanent flux density
Saturation magnetization
Winding capacitance
Core distortion factor
Relative disaccommodation coefficient DF = d/i
Disaccommodation coefficient
Activation energy
Frequency
Cut-off frequency
Upper frequency limit
Lower frequency limit
Resonance frequency
Copper filling factor
Air gap
RMS value of magnetic field strength
Peak value of magnetic field strength
DC field strength
Coercive field strength
Hysteresis coefficient of material
Relative hysteresis coefficient
RMS value of current
Direct current
Peak value of current
Polarization
Boltzmann constant
Third harmonic distortion
Circuit third harmonic distortion
Inductance
mm2
mm2
nH
nH
mm2
mm2
= 10–6
Vs/m2, mT
Vs/m2, mT
Vs/m2, mT
Vs/m2, mT
Vs/m2, mT
Vs/m2, mT
Vs/m2, mT
F = As/V
mm–4.5
J
s–1, Hz
s–1, Hz
s–1, Hz
s–1, Hz
s–1, Hz
mm
A/m
A/m
A/m
A/m
10–6 cm/A
10–6 cm/A
A
A
A
Vs/m2
J/K
H = Vs/A
Symbols and terms
Ferrites and accessories
Symbols and terms
606/13
Symbol Meaning Unit
L/L
L0
LH
Lp
Lrev
Ls
le
lN
N
PCu
Ptrans
PV
PF
Q
R
RCu
Rh
Rh
Ri
Rp
Rs
Rth
RV
s
T
T
TC
t
tv
tan
tanL
tanr
tane
tanh
tan/i
U
Û
Ve
Z
Zn
Relative inductance change
Inductance of coil without core
Main inductance
Parallel inductance
Reversible inductance
Series inductance
Effective magnetic path length
Average length of turn
Number of turns
Copper (winding) losses
Transferrable power
Relative core losses
Performance factor
Quality factor (Q = L/Rs = 1/tanL)
Resistance
Copper (winding) resistance (f = 0)
Hysteresis loss resistance of a core
Rh change
Internal resistance
Parallel loss resistance of a core
Series loss resistance of a core
Thermal resistance
Effective loss resistance of a core
Total air gap
Temperature
Temperature difference
Curie temperature
Time
Pulse duty factor
Loss factor
Loss factor of coil
(Residual) loss factor at H 0
Relative loss factor
Hysteresis loss factor
Relative loss factor of material at H 0
RMS value of voltage
Peak value of voltage
Effective magnetic volume
Complex impedance
Normalized impedance |Z|n = |Z| /N2 (le/Ae)
H
H
H
H
H
H
mm
mm
W
W
mW/g
K/W
mm
°C
K
°C
s
V
V
mm3
/mm
Symbols and terms
Ferrites and accessories
706/13
All dimensions are given in mm.
Surface-mount device
Symbol Meaning Unit
F
e
r
B
i
s
0
a
app
e
i
p'
p"
r
rev
s'
s"
tot
l/A
Cu
Temperature coefficient (TK)
Relative temperature coefficient of material
Temperature coefficient of effective permeability
Relative permittivity
Magnetic flux
Efficiency of a transformer
Hysteresis material constant
Hysteresis core constant
Magnetostriction at saturation magnetization
Relative complex permeability
Magnetic field constant
Relative amplitude permeability
Relative apparent permeability
Relative effective permeability
Relative initial permeability
Relative real (inductive) component of (for parallel components)
Relative imaginary (loss) component of (for parallel components)
Relative permeability
Relative reversible permeability
Relative real (inductive) component of (for series components)
Relative imaginary (loss) component of (for series components)
Relative total permeability
derived from the static magnetization curve
Resistivity
Magnetic form factor
DC time constant Cu = L/RCu = AL/AR
Angular frequency; = 2 f
1/K
1/K
1/K
Vs
mT-1
A–1H–1/2
Vs/Am
m–1
mm–1
s
s–1
Symbols and terms
Ferrites and accessories
806/13
The following applies to all products named in this publication:
1. Some parts of this publication contain statements about the suitability of our products for
certain areas of application. These statements are based on our knowledge of typical re-
quirements that are often placed on our products in the areas of application concerned. We
nevertheless expressly point out that such statements cannot be regarded as binding
statements about the suitability of our products for a particular customer application.
As a rule, EPCOS is either unfamiliar with individual customer applications or less familiar
with them than the customers themselves. For these reasons, it is always ultimately incum-
bent on the customer to check and decide whether an EPCOS product with the properties de-
scribed in the product specification is suitable for use in a particular customer application.
2. We also point out that in individual cases, a malfunction of electronic components or
failure before the end of their usual service life cannot be completely ruled out in the
current state of the art, even if they are operated as specified. In customer applications
requiring a very high level of operational safety and especially in customer applications in
which the malfunction or failure of an electronic component could endanger human life or
health (e.g. in accident prevention or lifesaving systems), it must therefore be ensured by
means of suitable design of the customer application or other action taken by the customer
(e.g. installation of protective circuitry or redundancy) that no injury or damage is sustained by
third parties in the event of malfunction or failure of an electronic component.
3. The warnings, cautions and product-specific notes must be observed.
4. In order to satisfy certain technical requirements, some of the products described in this
publication may contain substances subject to restrictions in certain jurisdictions (e.g.
because they are classed as hazardous). Useful information on this will be found in our Ma-
terial Data Sheets on the Internet (www.epcos.com/material). Should you have any more de-
tailed questions, please contact our sales offices.
5. We constantly strive to improve our products. Consequently, the products described in this
publication may change from time to time. The same is true of the corresponding product
specifications. Please check therefore to what extent product descriptions and specifications
contained in this publication are still applicable before or when you place an order. We also
reserve the right to discontinue production and delivery of products. Consequently, we
cannot guarantee that all products named in this publication will always be available. The
aforementioned does not apply in the case of individual agreements deviating from the fore-
going for customer-specific products.
6. Unless otherwise agreed in individual contracts, all orders are subject to the current version
of the "General Terms of Delivery for Products and Services in the Electrical Industry"
published by the German Electrical and Electronics Industry Association (ZVEI).
7. The trade names EPCOS, BAOKE, Alu-X, CeraDiode, CeraLink, CSMP, CSSP, CTVS,
DeltaCap, DigiSiMic, DSSP, FilterCap, FormFit, MiniBlue, MiniCell, MKD, MKK, MLSC,
MotorCap, PCC, PhaseCap, PhaseCube, PhaseMod, PhiCap, SIFERRIT, SIFI, SIKOREL,
SilverCap, SIMDAD, SiMic, SIMID, SineFormer, SIOV, SIP5D, SIP5K, ThermoFuse,
WindCap are trademarks registered or pending in Europe and in other countries. Further
information will be found on the Internet at www.epcos.com/trademarks.
Important notes
