TMC5160 heat sinks


Khalid Baheyeldin
 

I finally got around to testing the TMC5160 (BigTree Tech V1.2).

They work fine on the FYSETC S6 without the need to manual put a wire CLK to GND.
Set IRUN to 675 (which is what I had the LV8729 set to), and left IGOTO and IHOLD
as OFF, for OnStep to calculate them.

They also run cool (42C maximum in brief testing, without the heat sink).

However, I noticed something odd. The heat sinks that come with it are long, and supposed
to cover the driver end to end on the long axis. But it will be raised by a tiny bit by the MOSFETS,
and will not touch the square copper pad at all.

See the image of this particular TMC5160 here.

One can buy the smaller square heat sinks like the ones that come with the TMC2130, and
they should fit the square copper pad, but will not cool the MOSFETS.

What did other people do with heat sinks for that driver?


Mike Ahner
 

On Mon, Nov 2, 2020 at 07:46 PM, Khalid Baheyeldin wrote:
But it will be raised by a tiny bit by the MOSFETS,
and will not touch the square copper pad at all
It's likely there is nothing in the chip that needs more heatsink than the copper pad. Remember the mosfets are now external and they are the high current heat source. So covering those with a heatsink makes sense, as does letting the copper pad heatsink take care of the chip itself.


Khalid Baheyeldin
 

On Mon, Nov 2, 2020 at 11:09 PM, Mike Ahner wrote:
letting the copper pad heatsink take care of the chip itself.
So, if the copper pad is not touching the heat sink, things are still good, since the chip would not output much heat, but the MOSFETs will.
Right?


Mike Ahner
 

That is correct as I understand it.


Mike Gore
 

Yes, only the mosfets need the heat sync , and only for high loads.( That is how mine are setup.) Another note, the larger external mosfets have lower on resistance then the 2130 internal mosfets so they do not get as hot for the same load.