FullBridge core


Can any one suggest please,

Which ferrite core should I use for full bridge dc dc converter from 48 V to 360 V for 5KW power?


Hold on one moment,
your reply is being sent

BogdNazar says:



The core selection represents one of the most relevant decisions in any magnetic design process.

In order to choose a proper size core for the specifications, I recommend you to use the Area Product methodology.


In this link you will find a more detailed explanation about the advantages and limitations of this approach, but generally speaking, what this methodology does is to "suggest" or "discard" cores in relation with the required specifications and the shape of the cores.

At page 8, starts the topic "Core Selection: Size", which I strongly recommend you to read, and the Ap formula is introduced.


These are the parameters that the formula requires:

  • Po, that is determined by the specifications
  • Frequency, that is determined by the specifications
  • Kf, the topology factor. In a Full Bridge a value of 0.017 can be assumed
  • deltaB. The flux density swing. Using ferrite cores this value should not surpass 0.3T.


Once you get the Ap value determined by the specifications, you need to find cores with an Ap value, determined by its shape, bigger or equal than the Ap from the specifications. This new Ap is calculated with the following formula:


Being Ae the effective area of the core and Aw the window area of the core.

However, this is only the beginning of the process. In order to continue the design, more information is required, such as the switching frequency and the duty cycle in which the transformer will work.


Nevertheless, in the link above, you should find enough information to complete your design properly. If you get stuck just ask again. Good luck!

Published: 5 months ago
Edited by erkansari on 5 months before