Currently reading the datasheet of these components, I wish to ask you some more information about the power-up sequence.
On page number 24 of the datasheet (revision C), I can read that the ideal power-up sequence is : 1.VSS, 2. VDD and then Va/Vw
But on the AD5272 FAQ (http://www.analog.com/en/digital-to-analog-converters/digital-potentiometers/ad5272/products/technical-documentation/index.html), under the question "Is there a power-up sequence?" I read that the power-up sequence is 1. VDD, 2. VSS and then Va/Vw
So I wonder which sequence is the right one? Is it really important ?
I thank you
The power sequence is important bc this avoid to stress the part.
It is always recommended to power the substrate of the circuit first.
As a simple example, when you connect your board to any supply, are you connecting first GND? or VDD?
In this case, the substrate is a n-well, so the first supply must be the most negative, in this case Vss.
If the substrate is p-well, the substrate is connected to Vdd.
Answering your question, the DS should have priority over any other document, so the correct supply sequence is Vss -> Vdd -> Va/Vw
Let me know if something is not clear, please.
Thank you very much.
That's exactly the answer I was expecting