OT - MOSFET choice

[Gusse]

Hi Scampy,

Based on IRF3708 datasheet, Rdson = 9.5mOhm (typ), Vgs= 4.5V, Id= 12A, therefore PCA9865 should be OK to drive FET without pre-driver stage. Gate resistor might need fine tuning. Ten(s) of ohm might be OK. Resistance on gate and gate input capacitance (~2-3nF), will make a RC-filter.

Gate capacitance is important parameter as Henrik stated. I didn't include it to my previous post due to fact that PCA9865 max output frequency is low (1526Hz).
IRF3708 applications are high freq DCDC (~3-6MHz switching freq), so there is no need to worry about that parameter too much.

With multi-FET packages it is more important to keep Rdson low if all FETs are on same time. It doesn't matter if it is through hole or surface mounted device, same rules applies.
Reserve enough PCB area for GND under the FET to do proper cooling.