High current switch vs slide switch + FET.

[silent]

Hello.

I have two boards in my project - #1 (main) and #2. I want to be able to manually cut off the power from #2 (drains 3A in peak). Is it a good design practice to use a small slide switch and a FET (2-way ON-ON;  [5V OR GND]---[R1]---[base of FET] )  or should i go with a large switch with higher current rating?

[T3sl4co1l]

If there's no special reason to do otherwise, I'd be surprised if the sw+FET were even cheaper, let alone easier to do.

Special reasons might include: limiting turn-on surge current or controlled ramp-down; sparkless switching (particularly for higher voltages in explosive environments); automated control, or as a future expansion option; fault current limiting; etc.

Special considerations include inrush current, peak dissipation, handling of fault current, extra voltage drop, additional current draw (at least a few microamps, due to the gate pullup resistor, depending on value and speed) and etc.

Tim

[silent]

I'd like to use a small smd switch with p-mosfet in SO8 instead placing a larger tht one. I think I'll go with FET.