I am building a replacement for a 4-20 mA receiver device. I plan to use an ATmega328P processor and minimal other circuitry, with an average total 5v supply current of less than 150 mA. I would like to power this off of the 24 vdc supply that is also used to power the 4-20 mA sender device using a D24V22F5 buck regulator.
This device will be in an equipment cabinet (with relays and other electronic equipment) in a room that can reach 100 degF in the summer time. I expect the inside of the cabinet could approach 45 degC. Am I likely to have problems with the D24V22F5 (and no heatsink or forced cooling) shutting down from over-temp in these conditions?