Q.The catalog says "The operating temperature is between -40°C to +85°C, but there are cases where this can vary depending on the material.” Does this mean that it can be used at over +85°C when there is quite a margin with the Curie temperature?
Ferrites and Accessories > Ferrites and Accessories > Ferrite Cores
The general temperature range of electronic components is sometimes applied for operating temperatures. In actuality, ferrite cores have a ”Curie temperature” so they can be used as magnetic bodies until they reach this temperature.
However, there are many power supply transformers where the bottom temperature of the core loss of the ferrites is between +80°C and +100°C, and there is the risk of a thermal runaway due to increased core loss --> heating --> increased core loss --> heating if they are used at temperatures of over +85°C.