what driver chip do i need for a irf4905 p-channel mosfet
FETs need a gate voltage &gt;2 to &gt;2.5 Vgs(th)max to guarantee low RdsOn. This is fundamental to all datasheets on FETs. The logic level types are Vgs(th)= Vt (aka) Vth ~ 1V for 3.3V operation.
Your choice of RdsOn depends on I^2*Ron losses, thermal resistance and prudent max junction temp rise &lt;&lt; 40’C.
Inductive loads required an equivalent higher current rated diode in reverse across drain to rail-switched whether you choose Lo or hi side switch.