I'm building a 256x64 pixel RGB led array using those P5 LED panels from china.
The display is up and running but i'm getting some display issues which i'm sure its just noisy 5V power
Each display block is PWMed with a 10mhz pixel clock, so they do have lots of high current spikes.
Up until now i've been running the screen from two ATX computer psu's.
I had to go through 4 or so before i found 2 that worked solid with no draw issues. (stable picture).
Others where causing issues such as dim rows, flickering or randomly missing a clock.
Now that the display code is working well i'm moving to a more finalized power system.
I have removed the computer power supplies and replaced them with something more permanent.
The display uses up to 2A per panel and there are 16 panels, so 32A at 5V which i will split over a few powersupply modules.
I want to use maybe 2 of these kind of DC modules.
https://www.digikey.co.nz/product-detail/en/tdk-lambda-americas-inc/I6A4W020A033V-002-R/285-2668-ND/6605121But from testing its clear i need some filtering as they are glitching the display like i had before.
I've tried just adding bulk capacitance at the PSU and at the LED ends, but it doesn't help.
The scope is showing this on the 5V rail at the LED array power connectors. (see scope pic)
400mV of noise on a 5V rail definitely seems like its the cause of the problem.
Does anyone have recommendations for how to filter this out?
The freq looks to be around 85Mhz