A customer of mine is repurposing a board that I designed for them several years ago, and we're running into some interesting issues.
One of the issues is that there's a master turn-on to the power section of the board that's operated by pulling the gate of a P-channel FET low. I just noticed that the thing is rated for a maximum G-S voltage of 20V
-- we had been putting 24V on it (oops), and now we're putting about 29V on it (bigger oops).
We're now seeing that part get hot at high current draw, but we've identified two other possible mechanisms for that happening. I'm trying to sort through the suspects to find a culprit.
How much does the maximum G-S voltage rating on a FET matter? Could it make a FET overheat at high currents, or would it just cause the whole thing to pop somehow?