Our customer are trying to keep 1.8V power line lower than 3.3V power line.
But 1.8V supply voltage will stop increasing at 0.8V 240us.
If our customer power up 1.8V like this, would it be problem?
It is difficult to give a definitive answer without seeing the full power up sequence. But if they power up all the 3.3 V supplies together, and all the 1.8V supplies together, and always keep the 3.3V supplies above the 1.8V supplies during the transition, it should be fine.
They must also make sure to keep the reset pin held low for at least 5ms after the supplies are all fully up and stable, as described in the datasheet (see Power Supply Recommendation section).
Checking with part specialist and provide an update soon
Are all the 1.8V supplies powered up simultaneously?
What is the status of the 3.3V supplies when this 1.8V supply transition occurs?
Is the power-up sequence respecting the recommendations in the datasheet (see Power Supply Recommendation section)?
If all the recommendations in the datasheet are respected, I wouldn't anticipate an issue with this 1.8V supply transition.
Thank you for you reply.
I will check to my customer but I think at this moment they are also trying to power 3.3V power.
But they will control the condition always 3.3>1.8V.
So I think the only specification is to keep 1.8V power lower than 3.3V power.
If our customer keep this condition, can I answer to my customer that it won't be any problem?
1.8V supplies powered up simultaneously.
Can I answer to my customer that it won't be any problem?
Thank you for your answer.
I understood what you said.
I will answer to my customer.
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