Prevent current flowing back that MX8M processor and peripherals

[bada]

I have checked the I.MX8 reference design and have a question. 

Som board and carried board share a common power supply 1v8 and 3v3 through connectors.

Is it to prevent current backflow？

Can i design a i.mx8 som board +5v only supply? i.mx8 processor and peripherals IO use different 3.3v and 1.8v power supply.Not the same power rail.

[JorgeCas]

Hello,

Could you please share the schematic section that you are referring for?

It is ok if you need to supply your board with +5v only, if you need different voltage levels for each IO interface just use PMIC/discrete regulators to supply it.

Best regards.

[bada]

1.documnet number sch-46441,i.mx8m nano reference board.2.documnet number sch-29420,i.mx8qm cpu card.
Processor and peripherals IO use the same voltage
levels only not same power rail.For example,peripherals
power up first ,but Processor io unpower the moment.
Do current back flow to Processor io power？

[JorgeCas]

Hello,

No, there is no issue with that connection. Just keep power levels in operating range, follow the power-up sequence and you will be ok.

Best regards.

[bada]

It's ok.Thanks.