SPEBlox heating issue

We ordered 2 sets of the SPEblox and currently testing it with the GIGeblox for our application.

We are seeing the SPEblox getting pretty hot on 2 chips. Can you provide the thermal power for these chips and is there any recommended heatsinks we can use to keep them cool.

Our application demands integrating these boards into a fanless enclosure that is IP54 rated for industrial applications. We would appreciate any guidance on thermal and mechanical mounting

SPEBlox does tend to get quite hot, which does somewhat limit operating temperature. The first way to solve this is to reduce the input voltage. Running the board at 10V will reduce the heat generated by the onboard DCDC regulator.

However, most of the heat comes from the two PHY chips on the board, U2 and U7.

Thermal specifications for both chips are below.

U2
Maximum operating temperature: +105°C
Chip size: 7x7mm
Max power dissipation: 537.2mW
Junction to case thermal resistance: 18.7 °C/W

U7
Maximum operating temperature: +125°C
Chip size: 6x6mm
Max power dissipation: 679mW
Junction to case thermal resistance: 22.2 °C/W

In this case, some passive cooling to help the chips dissipate the heat into the air is going to be enough to reduce the cooling. A good choice would be the V5618C, which is a 23mm x 6.35mm heatsink that can be placed across both chips.

You would need either some type of thermal tape (like this) or a thermal epoxy (like this) if your application is going to be subject to vibration.