Mosfet Current verification

Hi everyone,

I have a basic electronic question.I am controlling the dc brushed motor which has a stall current 8.2A at 6v battery Ni-mH. I chose IRL3803 Mosfet where the gate from Arduino UNO(5V).

My question: 1.How much current rate from IRL3803 at 4.5v or 10V have? 2. whats difference between choosing 1 MOSFET or paralleling 3 Mosfet? 3. I have calculated the power dissipation. whether my calculation is correct?

P= I^2*R_(DS(on)) where resistance drain to source at 4.5v is 0.009 ohm P=0.6watts

Thanks in advance

This datasheet is the first Google hit I found. It may be different to the datasheet you're looking at.

1) It doesn't have 4.5V shown but the chart in Fig1 shows you can get 100A (for 20 microseconds) at 4V drive. 10V will give you 200-300A

2) If you need more, then buy a bigger one. More in parallel does work, but it's more effort to wire them all up.

3) Your calculation looks correct. The thermal resistance is 62 degrees per watt, so 0.6W will heat it up 37 degrees above ambient. Assume it's 40C inside your electronics box then the MOSFET will be at 77 degrees. It's rated up to 175 degrees, so this is no problem for it.