Always-on power domain voltage

Lets assume - I have 2 voltage domain - out of which 1 is always-on. My chip has 1.2V & 3.3V

Now my question is - Why always-on power domain's logic will sit on 3.3V? why not 1.2 V

Please share your experience, if you want to add please do so..


Thank you.

Your always on domain can be anything you want. not sure where you got your 3.3V constraint from.

I believe you are mixing the concepts of IO voltages and power domains.

Thanks for reply.. ~Sam

ThisIsNotSam said:

Your always on domain can be anything you want. .

Click to expand...

Some chips what I saw have alway-on domain placed with higher voltage. (if it has 3v & 5v, then AoN domain is on 5v)
that is why this query came up..

ThisIsNotSam said:

not sure where you got your 3.3V constraint from.

Click to expand...

- What made you to write this comment.. whats wrong in 3.3v. I am 100% sure that there is some significance in your thoughts - please share..

ThisIsNotSam said:

I believe you are mixing the concepts of IO voltages and power domains.

Click to expand...

- again would like to ask same quest (- What made you to write this comment.. )
what made you to think of IO voltage..?

if you give insights, some of my myth and gaps will be filled... Thanks..

vcnvcc said:

Thanks for reply.. ~Sam


Some chips what I saw have alway-on domain placed with higher voltage. (if it has 3v & 5v, then AoN domain is on 5v)
that is why this query came up..



- What made you to write this comment.. whats wrong in 3.3v. I am 100% sure that there is some significance in your thoughts - please share..




- again would like to ask same quest (- What made you to write this comment.. )
what made you to think of IO voltage..?

if you give insights, some of my myth and gaps will be filled... Thanks..

Click to expand...

3.3V is a typical IO voltage. I am now 100% sure you don't know the difference between IO power supply and core power supply and how power domains work.

Well first of all thanks for reply!

I looked at your post 3 times consecutively since I opened your post today, kept “smiling in mustache”!!

About post: I think I have asked/written incorrectly, but more info I can’t put here...anyway thanks again for reply..