November 9, 2010

Inductors: Compact flyback transformers (TDK-EPC Corporation)

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TDK-EPC, a group company of the TDK Corporation, presents a new series of compact SMD flyback transformers from EPCOS for space-saving power supplies. Thanks to their EFD cores, they enable insertion heights of only 8.65 to 14.8 mm, depending on the transformer type.

The new B82802* series comprises three core sizes and covers the power range between 12 and 55 W. These SMD flyback transformers are suited for input voltages of between 36 and 60 V at a clock frequency of 100 kHz and a duty ratio of up to 50 percent. In the standard versions, the output power is divided up among two or three windings. This results in voltages of 3.3 V at currents of 1.2 to 3.3 A; 5 V at 0.8 to 5.5 A and 12 V at 0.5 to 2.3 A. Customer-specific configurations of the output voltages and powers are also possible. The transformers are designed for an operating temperature of between -40 and +125 °C and tested for breakdown at 1500 V AC.


  • Flyback converter: a special switching converter topology. These DC/DC converters are also known as buck-boost converters. Their advantage lies in the electrical separation between input and output voltage. Flyback converters are used at powers of up to 250 watts.

Main applications

  • DC/DC converters for industrial and consumer electronics as well as communications technology.

Main features and benefits

  • Low insertion height of 8.65 to 14.8 mm
  • Powers up to 55 watts
  • Up to three output voltages

Key data


Vout1/ Iout1


Vout2/ Iout2


Vout3/ Iout3




Ordering code

EFD 155/ 1.212/ 0.512B82802A0012A215
EFD 153.3/ 1.25/ 0.812/ 0.3312B82802A0012A315
EFD 205/ 3.012/ 1.2530B82802A0030A220
EFD 203.3/ 3.05/ 2.012/ 0.8330B82802A0030A320
EFD 255/ 5.512/ 2.355B82802A0055A225
EFD 253.3/ 5.55/ 3.712/ 1.555B82802A0055A325

About TDK-EPC Corporation

TDK-EPC Corporation (TDK-EPC), a TDK group company, is a leading manufacturer of electronic components, modules and systems headquartered in Tokyo, Japan. TDK-EPC has emerged from the combination of the electronic components business of TDK and the EPCOS Group and markets its products under the product brands, TDK and EPCOS.

The product portfolio includes ceramic, aluminum electrolytic and film capacitors, ferrites and inductors, high-frequency components such as surface acoustic wave (SAW) filter products and modules, piezo and protection components, and sensors. With this product spectrum TDK-EPC offers a broad range of products and solutions of outstanding value from a single source and focuses on demanding markets in the areas of information and communication technology and automotive, industrial and consumer electronics. The company has design and manufacturing locations and sales offices in Asia, Europe, and in North and South America.

Further information on the products can be found under

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