Redpitaya Forum

The hardware spec lists 30 C as the temperature limit. I see that Zynq maximum operating temperature is 80 C. Why is there such a large discrepancy between these maximum temperatures?

That's because they are completely different things physically. The ZYNQ produces heat while operating, and in order to keep it below its maximum operating temperature, this heat has to be dissipated into the environment. A major factor in the efficiency of heat dissipation is the difference between the device temperature and the ambient temperature. If the ambient temperature is close to the device temperature, very little energy would be transferred away from the ZYNQ, causing it to get hotter. When it gets hotter, more energy flows from it to the environment, until a kind of equilibrium is established (assuming the environment can take the energy without becoming noticably hotter itself).

So the allowed ambient temperature is chosen low enough to enable an equilibrium that is well below the maximum operating temperature of the device, with a good margin of safety.

Another important factor in the efficiency of heat dissipation is the method of cooling. Passive cooling with a heat sink is ok, but with a fan mounted, you could do quite a bit better, meaning higher permissible ambient temperature, because you can get more energy off the device.

Btw. My device after 30 minutes of working.

Nice picture!

After reading this blog post, I immediately bought a cooler fan for my Red Pitaya.

With the heat sink installed by default, the temperature of the ZYNQ chip is very close to the maximum operating temperature (82 C).

Currently, I'm using a 30x30x15mm fan and the temperature of the ZYNQ chip is around 35-40°C.

You can find links to a couple of cooler fans that I bought for Red Pitaya at this link. They both fit exactly the heat sink on the Red Pitaya board.