DS90UB914A-Q1: t1 - VDDIO to VDD_n Delay

Kuramochi Tadahiko

Guru 28715 points

Part Number: DS90UB914A-Q1

Hi,

The t1(VDDIO to VDD_n Delay) is specified in the datasheet.

And the power sequence on my customer's circuit shows below.

In this case, does t1 begin from "a" point or "b" point?

If it is "b", I think that it is no problem.

If it is "a", I think that it should be improved.

Best Regards,

Kuramochi

0 Hamzeh Jaradat over 7 years ago

Hello Kuramochi,

I think this should be improved. VDD_n can be high at the same time or later but not before VDDIO.

0 Kuramochi Tadahiko over 7 years ago in reply to Hamzeh Jaradat

Guru 28715 points

Hamzeh-san,

Thank you for your quick response.

Does it mean that the beginning point is "a"?

Best Regards,

Kuramochi

0 Hamzeh Jaradat over 7 years ago in reply to Kuramochi Tadahiko

Kuramochi-san,

normally the correct starting point should be b), but because a is exceeding the 180mV level it may cause issues.

Interface forum