MOSFET Cut-off

[brentab]

Hello all!
From my understanding!  a P-channel Enhancement MOSFET, (The cut-off region) The Gate potential must be more positive with respect to the Source.
As a example we will take the RF9Z24NPBF FET.

From the data sheet.

1. Vgs - Gate-Source Breakdown Voltage: = 20 V
2. Vds - Drain-Source Breakdown Voltage: - 55 V

? From the above statement, If i wanted a Drain-Source Voltage of 40 volts, how can i cut the FET off when i can only supply 20 volts maximum to the gate.
Thanks brentab

[disneyjoe7]

I believe you're fine with that MOSFET has the max is 55v and your need is 40v. Thinking you don't need such a high voltage to trigger it but I'm sure a resistor is needed to drop the gate trigger voltage.