Author Topic: How to connect to power plane  (Read 2201 times)

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Offline pcblearnerTopic starter

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How to connect to power plane
« on: April 21, 2015, 12:35:14 pm »
Hello

I have a project where I power a lot of LEDs - about 10A (50W) worth. I am making a 4 layer PCB with a power plane. A DC power socket is mounted through-hole on the PCB. That connects to a power switch. I want the output of this power switch to connect to the power plane. What's the best way to do this?

Obviously my first thought is a via, but I don't know how big it needs to be to handle the current. The calculators on the net (like Saturn) use terms I don't understand like: "Via Hole Diameter" (Is that the drill hole diameter or the total via diameter?) and "Ref Plane Opening Diameter" (??).

Also, if the required via ends up have a really large diameter, is there a preferred way to use closely spaced smaller vias connected together by track?

I guess at the end of the day, I'm just trying to figure out the safest via size for distributing 10A through to the internal power plane.

Thanks for your help in advance.
 

Offline tszaboo

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Re: How to connect to power plane
« Reply #1 on: April 21, 2015, 12:52:42 pm »
What? 4 layer boards for LEDs?
Just order the boards with thicker copper if you are afraid of the voltage drop, which you should not be, these are LEDs, and they have a series resistor or a current source running them.
Use multiple vias if you have to. 10A easily goes through 7-15 0.5mm via like they are not even there. It is not like the PCB really going to cost more for more vias (at least not for people who make <1000 boards).
 

Offline pcblearnerTopic starter

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Re: How to connect to power plane
« Reply #2 on: April 21, 2015, 01:18:03 pm »
What? 4 layer boards for LEDs?
There are other ICs as well, and I thought it was a good idea to go 4 layer to have a solid ground plane for EMC minimisation..
Quote
Just order the boards with thicker copper if you are afraid of the voltage drop, which you should not be, these are LEDs, and they have a series resistor or a current source running them.
Use multiple vias if you have to. 10A easily goes through 7-15 0.5mm via like they are not even there. It is not like the PCB really going to cost more for more vias (at least not for people who make <1000 boards).
Thanks. I think I had confused myself. I was worried about via current ratings.. but when the via is directly part of the power plane itself, current ratings aren't such a problem anymore!!
 


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