Hi Hazel,
what is the recommended specified temperature?
The OPA548's performance is specified up to 85C in the datasheet, and these are guaranteed performance up to 85C. The power amplifier is able to operate up to 125C, but there will be some performance degradation, and it depends how hot or the amount of heat dissipation inside of the package.
You would need to calculate the amount of heat dissipation occurred inside of OPA548, as Clemens indicated. The heat dissipation depends on several operating parameters, such as supply voltage, load type, output amplitude, waveform types, quiescent current etc.. So you would need to estimate the heat dissipation under the worst case operating environment, or you would check out SOA curves and do a quick estimation if OPA548 may be suited to drive the application load.
If you have the design requirements, we can simulate the heat dissipation with Tina, and approximate the OPA548's feasibilities.
If you have additional questions, please let us know.
Best,
Raymond
