Need help to find replacement for power mosfet IRF7303
Virtually all enhancement mode MOSFETs are functionally equivalent but some will be better choices than others. Try and find a MOSFET with these performance characteristics: -


The same or lower on-resistance for a given range of gate voltages likely to be applied in the MAXIM circuit described on page 10
The same or higher maximum drain-source voltage rating
The same or higher maximum drain current
At least the same package type but double check also that the thermal resistance is at least as good
Gate capacitance about the same as the obsolete device. +/- 50% should be OK


It may take an hour or two but when you have something you think will do the job, leave a comment with links to the old part's and the new part's data sheets for a quick double check.