FEDEVEL
Platform forum

Shubham , 04-22-2024, 12:50 PM

I'm doing layout of 48V to 12V 65A buck converter PCB. What will be copper thickness of PCB for 4 layer and 2 layer PCB ? I'm using NBM2317S60D1565T0R DC- DC Converter IC.

SkyDvv , 04-22-2024, 07:33 PM

I suggest using Saturn PCB, there's PCB trace current calculator there, see you options and decide

Sniper2 , 04-22-2024, 07:38 PM

man this will be expensive and complex

QDrives , 04-22-2024, 07:56 PM

What minimum trace width and clearance does the board need?
Copper thickness is one thing, but the thicker the copper, the wider the traces and clearances need to be too.

Shubham , 04-23-2024, 05:43 AM

Yes it is expensive but I need Compact and minimum form factor PCB

Sniper2 , 04-23-2024, 06:13 AM

At that current I am not sure if it is a pcb or just a conveniently shaped piece of copper

Shubham , 04-23-2024, 06:43 AM

Input voltage is 48V and Output is 12V and I'm preferring Copper pours

Mini , 04-23-2024, 12:47 PM

Im working on something similar. I would suggest you to keep traces as short and wide as possible(of course using polygons). I personally will not use solder mask on top of those high current polygons and will solder copper plates on top of them. This way you can handle a lot of current without using a lot of space.

Robert Feranec , 04-23-2024, 01:22 PM

Saturn PCB can help and also, some time ago I created this video, can help too: https://www.youtube.com/watch?v=LQ20GBonRmA I would use saturn for some initial numbers, then build it as quickly as possible and then used thermal camera a measured the temperature. If needed, I would then adjust the stackup and PCB. If you use 4 layers, you can double the planes (route the same planes on multiple layers), but keep in mind, currents will not be spread equally, in my opinion it will be more like: the larger copper on output, better heatsink it will be.

Shubham , 04-24-2024, 02:14 PM

HERE My Layout

Shubham , 04-24-2024, 02:14 PM

QDrives , 04-24-2024, 03:41 PM

I would suggest L1 to be fully Gnd.
Do keep in mind the DC and AC bias of the ceramic capacitors and the ripple current of the aluminium (electrolitic / polymer) ones.
I do not think F1 is capable of correctly protecting your input. A fast blow would blow charging the capacitors and I do not think a slow blow is available in 20A.

Robert Feranec , 04-24-2024, 03:43 PM

I also would try to have at least 1 solid ground