I'm involved in a product design (on the mechanical side, to be clear that I'm not an EE) where we need a very compact ac-dc switching power supply that will take 90-300vac, 50-60hz and output 5 watts at 12 volts. From a mechanical engineering perspective, it would be extremely advantageous if this power supply could deliver this power while operating for extended periods of time (many hours) at up to 105 °C ambient air temperature.
Just to make this more challenging our module would need to fit into a space about 15mm high, 25mm wide, and around 50mm long—so a really tight fit. The supply will need to be certified, so details like isolation (3000VAC) and noise that would effect wifi and Bluetooth radios needs to be controlled.
What I would like to know is what kind of considerations would go into whether designing such a power supply is feasible? For example, my limited understanding is that the capacitors are usually the components that limited temperature rating and reliability, but it also seems like there has been significant advancement in high-temperature ceramic and tantalum capacitors that would make such a power supply feasible today (although perhaps relative expensive).
Thank you in advance for any perspective you can provide.