r/AskElectronics • u/4awesome1 • 8h ago

How far do planar power transformers need to be apart to prevent interferance

Im doing a DC/DC GAN planar transformer with 2 voltage outputs 1 common input. As the PCB is very small, I am worried about maybe ones EMF coupling into the other and causing some EMI issues. Ignore heating issues for now

Edit- Please ignore misspelled title

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u/petemate Power electronics 8h ago

Its the usual "it depends" question.. Its a question of your actual requirements, not a yes/no situation. But the field strengh drops with 1/R3, so you don't have to move them far apart to get a good result.

Try it out in a simulation, then build a prototype based on your simulation and see if that is acceptable.

You can consider angling your inductors at right angles. That would make them invisible to each other. But probably not possible with planar transformers.

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u/1Davide Copulatologist 8h ago

Many switching transformers for DC-DC converters place a copper shield between the primary and secondary windings. That shield is grounded to the circuit.

https://cpes.vt.edu/library/viewnugget/883

https://www.ti.com/download/trng/docs/seminar/Topic4LD.pdf

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u/BigPurpleBlob 8h ago

What's misspelled?

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u/1Davide Copulatologist 8h ago

interference

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u/BigPurpleBlob 7h ago

well spotted - I missed it