TPS54302 prevent powering the circuit from regulator's output

[evansg]

I use the TPS54302 a synchronous step down converter in a couple of my circuits and I'm wondering how I can prevent the following scenario:

If you accidentally provide voltage to the output (lets say 12V), the circuit is powered (with these 12V) as the voltage runs through the coil and the regulator.
The regulator is not damaged until the current reaches its maximum (in this case 3Amps). After that regulator dies with the "magic smoke".
Is there any way or an easy circuitry to prevent a user to accidentally power the circuit from the regulator output? I use the same DC sockets (2.1mm) for input and output
and unfortunately this cannot change easily.

[sdouble]

I usually solve this kind of issues in putting 2 little stickers above or below the barrel connector : one writes "input" and the other one "output"

[magic]

You mean, somebody connects power to the output and load to the input and a parasitic diode in the regulator blows it up?

Bypass the regulator with a reverse Schottky diode, but user's load will then see 11.7V instead of 8V.
Add a diode in series with the input and screw efficiency.
Figure out some "ideal diode" protection circuit which will work even in absence of 12V power.
Input and output connectors shouldn't be same sex even if they are same size.

[evansg]

Not exactly.
User accidentally plugs the 12V DC jack to this regulator's output and whole circuit works bypassing the main DC input. I need to find a way to stop this.

[Peabody]

Are you saying your 8V circuit actually tolerates being powered at 12V?  I should get you to design my circuits.

[Someone]

Not exactly.
User accidentally plugs the 12V DC jack to this regulator's output and whole circuit works bypassing the main DC input. I need to find a way to stop this.

This has been solved in other systems with a "crowbar" circuit, but to provide sufficient protection while still working as a power output can get large/expensive/complex.

[Hiemal]

Would something like this work?

http://tinyurl.com/yxt5wbzh simulator version