... use a single device in a TO227 package
Did you perhaps mean a
TO247 package instead of TO227? And, BTW, where does the DUT connect? Between the V
cc supply and the MOSFET drains or somewhere else?
I already posted a link for the schematic. If you read ALL the posts you will understand better.
Sorry, I somehow missed your schematic of the op-amp negative feedback driving the MOSFET gate, based on the voltage drop across the current shunt resistor in series with the MOSFET source. I hope you took to heart the comments by other posters regarding op-amp rail-to-rail operation and low offset voltage requirements. Some "simple" unity-gain op-amp circuits can be a real bitch kitty to implement correctly in hardware. It becomes almost impossible without adequate test equipment and experience.
I did read (and continue to read) ALL the posts, but understanding eludes me. If you suspect oscillation is causing op-amps and MOSFETs to explode, an oscilloscope can quickly confirm this and perhaps help to troubleshoot the cause. However, it appears from this side of the keyboard that "hot spots" as described by the Wong site I linked to in post #18, that you apparently re-discovered and re-posted in your post #20 are the real contributing factors. As for your statement:
The issue is not the heat like a said a lot of times. There is no time for the MOSFET to get warm...
If the MOSFET case "explodes"
as shown in the image you uploaded, there was certainly enough time for the MOSFET "to get warm" enough. So, on top of other lack of knowledge you appear to exhibit, let's add ignorance of thermodynamics.
Reading this thread feels like a visit to one of the Twilight Zone television series episodes... so maybe I am not in the good domain.