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An n-ch depletion MOSFET is a different thing to a n-ch enhancement mode MOSFET. You can't convert it.
N-ch depletion needs a negative voltage to fully turn it off, whereas a n-ch enhancement device doesn't.
They are made differently at the physical level.
A silicon n-cannel depletion mosfet is built around a single p-n junction, which you can't forward bias. Being so, Vgs must be negative or zero. You may make it slightly positive by a few tenths of volt but, as you know from a simple diode, it will start to conduct soon.
A silicon n-cannel depletion mosfet is built around a single p-n junction, which you can't forward bias. Being so, Vgs must be negative or zero. You may make it slightly positive by a few tenths of volt but, as you know from a simple diode, it will start to conduct soon.
You are referring here to a JFET. Depletion mode FETs don't use a reverse-biased PN junction to create pinchoff, but rather they have an isolated gate. This means Vgs can be greater than zero, causing channel enhancement.
That will depend on the gate oxide thickness of the specific MOSFET. I wouldn't generally do anything that's not specified in the datasheet, but I would assume it should be able to withstand at least the threshold voltage +Vp in the positive direction.
You are referring here to a JFET. Depletion mode FETs don't use a reverse-biased PN junction to create pinchoff, but rather they have an isolated gate. This means Vgs can be greater than zero, causing channel enhancement.
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