diodes
If I apply an current source into the the cathode of a diode (current flow into cathode), what can possibly happen to the diode.
For the cuicuit below, when the FET is OFF, how does the battery current flow.
Will the current flow through the diode while it's in reverse region.
So, you reverse the bias and the battery begins pulling electrons out of the N type silicon and holes out of the P-type silicon *, eventually the area around the junction becomes charged up like a capacitor and the current stops flowing.
(*) you could picture this as filling the holes with electrons, but either way because of the electric field of the battery the holes move to the metal, and then accepting an electron from the metal, they disappear.
You're about 1/5th the way from the center on the left of the graph. You'll get a marginal reverse current, but it's so little it wouldn't matter to much electronics. Your battery would drain ever so slowly. Internal battery drain current would probably be higher. So basically your circuit does nothing.
Best Answer
Which diode?
I am going to assume you means #1 as the other's are not connected to anything and this appears to be part of either a phase leg or some pulled down load. In future please be concise...
Depends. Is this a theoretical case such that "ideal current sources" exist then the voltage associated with such an ideal current source could increase to infinite voltage to ensure the constant current would flow. This would cause a real diode to avalanche and be damage. But if we are contemplating ideal components then the diode could be ideal and thus could block infinite voltage and equally the FET could block infinite voltage.
If you are discussing a hypothetical load at the Drain of the FET then as long as the blocking voltage of the diode (and the FET) are higher than the forcing voltage behind whatever can source current... nothing will happen, at this part of the circuit. there will be some leakage current flowing, the value of which depends on the specific device.
What battery? there is no battery.