amplifier temperature cut off

Dear All, I would like to understand the standard temperature cutoff in car amplifiers. Do we have any standards on this? As far as my knowledge goes standard values may be 70deg for cut off and should turn on @ 60deg. In India we have extreme temperatures is it ok to design an amplifier to turnoff @ 90 deg temperature? Please let me know the standard values on this. Thank you. KuretiK. Venugopal Rao

It's probably not so much a case of having a standard temperature, but rather a good compromise. The hotter a component gets, the sooner it fails. EG - it may be that output transistors double their failure rate for every 10°C increase in temperature. (Or is it every 15°C?) In hot climates it is common to raise operational temperatures, otherwise the item would cut out too often. But that comes at the expense of shorter life. It's one of the "costs" of hotter climates. The temperature selected also depends on the component, and its heatsink size or efficiency. Some components are constructed for better heat tolerance.