I'm using the IRF7422 (P Mosfet - warning opens a *.pdf) FETKY and I'm experiencing a strange issue.
I am pulling the gate high to +5V which should theoretically cause the source-drain channel to stop conducting. However, if I subsequently measure the voltage present at the source I get 4.5 V. It seems whatever voltage is present at the drain node is fed back to the source with a 0.5V drop. Is this to be expected? There is nothing else connected to the source node.