Limitation is not listed in a datasheet, is the constitution of power supply such as follows possible?
Case1 VDD=1.2V OFF VDD33=3.3V OFF SDRAMC_VDD1P5=1.5V ON
Case 2 VDD=1.2V ON VDD33=3.3V ON SDRAMC_VDD1P5=1.5V OFF
Regarding "Case 2: VDD=1.2V ON, VDD33=3.3V ON, SDRAMC_VDD1P5=1.5V OFF".
Yes, the case when SDRAMC_VDD1P5 is not applied (but VDD and VDD33 are) is possible.
I replied "impossible" and sent the scope screenshots because I thought you also meant the sequence:
That is why I replied "1.2V is generated from 3.3V".
If you only meant their presence, without sequence, then this case is indeed possible.
Best regards, Naoum.
Sincerely yours, Naoum Gitnik.
Thank you for your reply.
I think that case1 does not have any problem from your answer.
Does case2 not have any problem?
Case 2 cannot happen - 1.2V is generated from 3.3V (see attachment).
I mistake, case1 and case2 was the reverse.
Does case1 not have any problem?
Regarding "Case1: VDD=1.2V OFF, VDD33=3.3V OFF, SDRAMC_VDD1P5=1.5V ON".
No problem with Case1 because the SDRAMC_VDD1P5 power rail order is NA (Not Applicable = Do not care = Arbitrary) in the sequence table.
In figure 4.Power supply, "SDRAMC_VDD1P5" seems to be provided from external power supply.
Therefore I think the case2 can happen.
Please correct me if I am missing some point.
Even a state of regular case1 (or case2) does not have any problem.
Is it right by the interpretation mentioned above ?
Yes, it is right.
Retrieving data ...