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ADV7181C power up leakage and power sequencing

Question asked by Boris.Yost on Sep 9, 2013
Latest reply on Sep 10, 2013 by Boris.Yost

I have a board with eight (8) ADV7181C's.  It happens to have a local power supply that has power sequencing.  The 1.8V core voltage comes up before the 3.3V, which is used for the I/O.  The timing on the 1.8 I think has no particular reason or requirement--others do.  There is a LOT of leakage onto the 3.3V rail before the 3.3V power supply kicks in.  It plateaus at 0.95 volts and hangs for a while.   The long plateau and slow power up is screwing up the power-up behavior of other devices on the board (but not the 7181c).  I have eliminated most (all?) other potential sources, and I'm left with the ADV7181C's as the most likely culprit.

 

So, the question is, does the ADV7181C have any power sequencing requirement?  (some other product line devices do)

Should it have a requirement that the I/O voltage be up before the core?

Can 3.3V start proportionally to the 1.8V?  (I can alter my board to make this happen.)

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