Heat sinking options for the A4983

Hello, my set of A4983 carriers (Pololu item #1201) are en route. From the nice product photos on the website it looks like the boards do incorporate the thermal vias recommended by the manufacturer, but I also saw references in this forum on adding heat sinks. What are the options for heat sinking this device? Can something be attached on the bottom of the board since that is where the thermal vias connect? Or is it better to attach something to the plastic case of the chip? I would expect the plastic chip to act as an insulator, but attaching a hunk of metal to the bottom of the board would be problematic.

Hello.

When the IC is overheating the plastic will get very hot. This means putting a heat sink on the package will help.

- Ryan

Hello.

You can add some heat sinking to the bottom of the board, too, but you do have to be careful not to short anything out. (There are various thin thermal conductors/electrical insulators out there for this sort of application.)

- Jan

Hey Ryan or Jan…
You can add some heat sinking
That’s what I need…I didn’t realize how small this board is! No not small…tiny…

How the heck am I going to put a heat sink on there!

Any Pololu products I can use?

Sorry to sidetrack your thread bbt5001 .
Arvin

We don’t carry any heat sink-related products. The heat sink you use can be bigger than the chip or board; just make sure you don’t short anything out. If your heat sink doesn’t have a good shape to avoid some of the other components, there are some products out there that look like foam rubber that are made for this sort of application. A search for something like heatsink gap filler might be a good starting point.

- Jan

gap filler. I’ll google that. Thanks.

If your looking for a simple and somewhat cheap option to passively cool your chip I would look at mosfet heatsinks designed for motherboards. There are some good options out there (ie. Enzotech MOS-C10 or the smaller MOS-C1)

@Princess Pussywillow - Thanks for the suggestion.

I’ve been wanting to post about the A4983 heat problem…it’s no problem.

I have a NEMA14 hooked up to it. I thought I’d give it a minute at low power, see how fast it heated up. Ended up running it all day. The motor got warm. The 4983 never got over ambient. Finger testing only. :wink:

The motor is 5v and at 0.75A and I was running it on 12v. Plenty of power for it’s size(full step). I’m experimenting with it as one of the axis on my current money pit as I try to make a inexpensive reprap (diy 3D printer).

Here it is running.

The best way would be to make your own heat sink but I have to agree with Princess_Pussywillow. I started using MOS-C1 which does the job well. You just have to tweak it a little to make it work. Good luck.