Can't Locate Vgd on Datasheet

[bostonman]

I'm looking for Vgd (gate to drain voltage) for a JANSR2N7616UB, but can't locate it on the datasheet.

Is this something that isn't typically specified?

[TheHolyHorse]

I don't think it is very common. Why is it that you need to know? If the nfet is used in the "correct way" it will exceed Vgs before Vgd anyway.

[Wimberleytech]

I'm looking for Vgd (gate to drain voltage) for a JANSR2N7616UB, but can't locate it on the datasheet.

Is this something that isn't typically specified?

Are you concerned with a maximum value to avoid failure?  For that you would just look at the VGS value in the max table.

[bostonman]

It's actually for an analysis and the customer is requesting we provide maximum stress voltages with that being one of the parameters.

[Jwillis]

This is a very basic understanding but it has to do with the construction of Mosfets.
In planar (IC) mosfets the Vds is equal  to the Vdg because the mosfet structure is symmetrical .  In discrete Mosfets The value of Vdg is much larger than Vds because of construction. So the specification is never usually stated because if the Vdg is exceeded the Vds has already been exceeded much more.

[magic]

Looking at the structure of either planar or trench vertical MOSFET, there is clearly an area where only thin oxide separates the gate from the drain. The drain-body junction must be engineered is such a way that under reverse bias, drain-side potential gradient is benign enough that voltage in the uppermost area of the drain near the gate doesn't exceed oxide breakdown limit.

It seems that the worst-case condition (which still doesn't result in failure for other reasons) is gate at -Vgs(max) and drain at +Vds(max), because then the gate-drain oxide is exposed to slightly more than +Vgs(max). Interestingly, this seems to imply that every MOSFET guaranteed to withstand such condition is also certain to withstand slightly more than Vgs(max) on its gate terminal when it is driven normally, i.e. gate positive with respect to source. Hmm.

Note that if you apply HV across drain and gate while leaving the source floating, leakage will presumably charge the source terminal up and cause oxide breakdown.