Magnetics modules for LAN applications
10/100 Base-T magnetics module
Series/Type:
B78476A1889A
Date:
March 2015
© EPCOS AG 2015. Reproduction, publication and dissemination of this publication, enclosures hereto and the
information contained therein without EPCOS' prior express consent is prohibited.
EPCOS AG is a TDK Group Company.
10/100 Base-T magnetics module
B78476A1889A
Dual port, power over ethernet
Features
Ferrite toroid, case and potting (UL 94 V-0)
Compliant with IPC/JEDEC J-STD-020D
Compliant with IEEE 802.3af
RoHS-compatible
Marking
EPCOS, middle block of ordering code, date code
Delivery mode and packing unit
24-mm blister tape,
330-mm ∅ reel (cardboard packaging)
Packing unit: 400 pcs./reel
Dimensional drawing
Layout recommendation
Dimensions in mm [inch]
Values without tolerances are nominal values for reference.
Please read Cautions and warnings and
Important notes at the end of this document.
Page 2 of 6
10/100 Base-T magnetics module
B78476A1889A
Dual port, power over ethernet
Pinning
Characteristics and ordering code
(electrical specifications at +25 °C)
Ordering code
B78476A1889A
Turns ratio (primary : secondary)
Inductance L
1CT : 1CT ±3%
350 µH min.
100 kHz, 100 mV, 8 mA DC bias
Voltage test Vtest
1500 V AC
50 Hz, 1 min
Insertion loss
1.2 dB max.
16 dB min.
14 dB min.
13 dB min.
12 dB min.
43 dB min.
37 dB min.
31 dB min.
43 dB min.
37 dB min.
33 dB min.
0.1 MHz ... 100 MHz
1 MHz ... 30 MHz
40 MHz
50 MHz
60 MHz ... 80 MHz
30 MHz
60 MHz
100 MHz
30 MHz
60 MHz
100 MHz
Return loss
Crosstalk
Differential to common-mode
rejection (DCMR)
Operating temperature range
0 °C ... +70 °C
Weight
Approx. 1.8 g
Please read Cautions and warnings and
Important notes at the end of this document.
Page 3 of 6
10/100 Base-T magnetics module
B78476A1889A
Dual port, power over ethernet
Cautions and warnings
For soldering conditions of SMD components please refer to JEDEC J-STD-020D.
If the components are to be washed varnished it is necessary to check whether the washing
varnish agent that is used has a negative effect on the wire insulation, any plastics that are
used, or on glued joints. In particular, it is possible for washing varnish agent residues to have a
negative effect in the long-term on wire insulation.
Washing processesmay damage the product due to the possible static or cyclic mechanical
loads (e.g. ultrasonic cleaning). They may cause cracks to developon the product and its parts,
which might lead to reduced reliability or lifetime.
The following points must be observed if the components are potted in customer applications:
– Many potting materials shrink as they harden. They therefore exert a pressure on the plastic
housing or core. This pressure can have a deleterious effect on electrical properties, and in
extreme cases can damage the core or plastic housing mechanically.
– It is necessary to check whether the potting material used attacks or destroys the wire
insulation, plastics or glue.
– The effect of the potting material can change the high-frequency behaviour of the
components.
Ferrites are sensitive to direct impact. This can cause the core material to flake, or lead to
breakage of the core.
Even for customer-specific products, conclusive validation of the component in the circuit can
only be carried out by the customer.
Display of ordering codes for EPCOS products
The ordering code for one and the same product can be represented differently in data sheets,
data books, other publications and the website of EPCOS, or in order-related documents such as
shipping notes, order confirmations and product labels. The varying representations of the
ordering codes are due to different processes employed and do not affect the specifications of the
respective products. Detailed information can be found on the Internet under
www.epcos.com/orderingcodes.
Please read Cautions and warnings and
Important notes at the end of this document.
Page 4 of 6
Important notes
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
requirements 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 we are either unfamiliar with individual customer applications or less familiar with them than
the customers themselves. For these reasons, it is always ultimately incumbent on the customer
to check and decide whether a product with the properties described 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 life-saving 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 Material
Data Sheets on the Internet (www.tdk-electronics.tdk.com/material). Should you have any more
detailed 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
foregoing for customer-specific products.
6. Unless otherwise agreed in individual contracts, all orders are subject to our General Terms
and Conditions of Supply.
7. Our manufacturing sites serving the automotive business apply the IATF 16949 standard.
The IATF certifications confirm our compliance with requirements regarding the quality
management system in the automotive industry. Referring to customer requirements and
customer specific requirements (“CSR”) TDK always has and will continue to have the policy of
respecting individual agreements. Even if IATF 16949 may appear to support the acceptance of
unilateral requirements, we hereby like to emphasize that only requirements mutually agreed
upon can and will be implemented in our Quality Management System. For clarification
purposes we like to point out that obligations from IATF 16949 shall only become legally binding if
individually agreed upon.
Page 5 of 6
Important notes
8. The trade names EPCOS, CeraCharge, CeraDiode, CeraLink, CeraPad, CeraPlas, CSMP, CTVS,
DeltaCap, DigiSiMic, ExoCore, FilterCap, FormFit, LeaXield, MiniBlue, MiniCell, MKD, MKK,
MotorCap, PCC, PhaseCap, PhaseCube, PhaseMod, PhiCap, PowerHap, PQSine, PQvar,
SIFERRIT, SIFI, SIKOREL, SilverCap, SIMDAD, SiMic, SIMID, SineFormer, SIOV, ThermoFuse,
WindCap are trademarks registered or pending in Europe and in other countries. Further
information will be found on the Internet at www.tdk-electronics.tdk.com/trademarks.
Release 2018-10
Page 6 of 6