@3V0: I have seen alot of hobby circuits use the 7805 for automotive applications, keyword there is "hobby". I am looking for something more robust, as you say for that environment.
@Diver300: I am aware of the dissipation factor and where it comes from.
@Willbe: I have a ST RBO40-40G protecting against load dump and other overvoltage transients, along with reverse voltage issues.
What I was wondering is if anyone has used a linear regulator in one of their projects without thermal shutdown, and if so, what current was being drawn, what was the heatsink they were using, etc.
I have decided to use a switching regulator up front, after the RBO, to regulate the voltage at 12V. The regulator, LTC3780, operates from 4-24V, able to bring the voltage up if it drops below 12V.
After that, I will decide to use either the linear or switching regulators based on the amount of current being drawn by the parts. If the amount is below 250mA, then I don't see an issue with using a TO-263 soldered to the copper.
Like I said, I have seen this in the device that is meant for the automotive environment, and from what I have seen inside, it does not look like there are heavy current hogs inside that device.
Thank you all for your input.