When do I need a heatsink with UbiSwitch?

– Copied from a customer email –

The 3D model of the UbiSwitch features a huge heatsink. When is the heatsink required?

The answer depends on…

  1. How many ports you’re using on UbiSwitch (relates to power consumption)
  2. The environmental conditions of UbiSwitch

UbiSwitch can function well without a heatsink or any airflow in room temperature (25C) conditions if you’re just using the eight gigabit ethernet ports. But the same cannot be said if the ambient conditions are 40-50C.

In a similar vein, using the 8 gigabit ports and the 3 10G ports at 25C draws a lot of power, and thus will need a heatsink at 25C ambient.

So, there is not a “one-size-fits-all” answer, it depends on your application.

See below (ignore the test jig it is fixed in, which has no impact on the measurements)

Using 8 GigaBit Ethernet Ports
Voltage = 32V
Current = 0.074A
Power = 2.22W
Temperature on chip = ~52C


Using 8 GigaBit + 3 10G Ethernet Ports
Voltage = 32V
Current = 0.418A
Power = 13.14W
Temperature on chip = ~105C


In this case, UbiSwitch will thermally overload, and then shutdown safely. It will reboot once the temperature has dropped. So no damage will be done, but it will not be reliable for networking.

In general, we advise all our customers to use the heatsink so they can be sure UbiSwitch will work in all cases. However if you can design your own thermal solution, or test in application, then you can use without our heatsink, so long as you have done the design consideration.

– Copied from a customer email –

But what about 100Mbps connections. Lets say the ambient temperature is 50 degrees.

See the forum post below for 100Mbps power consumption.

It will be around the same or less power consumption as using 8 gigabit connections.

You would likely be fine without a heatsink at 50C, but we would still suggest using one. (I’m assuming ground level pressure and RH between 10% and 90%