Ferrite Bead Between VDD_SOC_IN and VDD_ARM_IN

[markwilliams]

Hi, I am just in the final checking stages of our iMX6 board design. The board will take solo, dual or quad processors and has the necessary common hardware design considerations.

We are using a single power supply for the SOC and ARM inputs. In some designs I see people have added a ferrite bead between VDD_ARM_IN and VDD_SOC_IN when feeding from the same supply.

Is this ferrite bead essential? I appreciate it may add some high frequency suppression on the supply line but it seems to just be in the SOC trace.

When routing as an 8-layer board it is nice to add a copper pour to cover both VDD_ARM_IN and VDD_SOC_IN in one, rather than split them into two seperate islands and put a ferrite outside the package area to join them.

Thanks, Mark

[igorpadykov · Accepted solution]

Hi Mark

I agree that with satisfactory board layout ferrite bead is not needed.

Seems purpose is to isolate VDD_ARM_IN island as producing more high

frequency noise.

Best regards
igor
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