The FQP4P40 is a 400V P-Channel MOSFET produced by Fairchild Semiconductor. This device has -3.5A, -400V, RDS(on) = 3.1Ω @VGS = -10 V, low gate charge (typical 18 nC), low Crss (typical 11 pF), fast switching, 100% avalanche tested and improved dv/dt capability.