regulating a raspberry pi power supply

[glennjarrett]

Hi
i have a raspberry pi 4 and Khadas tone board
i want to power the pi via the original power supply but i would like to give the tone board a low noise supply to improve the sound .
what i want to know is if i split the power from the supply and feed it into a buck converter board set at 5v to 7v out to feed the tps7a4700 ultra low noise regulator board set at 5v to power the tone board ? would this be ok ? see pic
the buck is there to give the regulator a bit of voltage to drop
CamScanner 05-22-2020 22.06.23_1 by glenn jarrett, on Flickr

 

[russc]

Have you read the manufacturers data?
"Each power path is controlled by a separate ultra-low noise CMOS linear regulator ".
Why do you think you can do better? They have done it for you.

 

[TNT]

And, as long as they share ground/0/earth, I don't think it will make a lot of difference really.

Sorry... computers don't mix very good with delicate analog circuitry.

//

 

[Vovk Z]

And, as long as they share ground/0/earth, I don't think it will make a lot of difference really.

+1. An ultra-low noise regulator won't help there much (in this particular case, I think). It can be much easier just to make a good filter for +5V (LCRC for example).