Greetings everyone,
I'd like to say I am inexperienced in this kind of stuff.
I wanted to select a N channel mosfet for switching a load (
which is a LED or LEDs in series) at 12v with maximum current of 300mA. The switching signal is PWM from a microcontroller with 100ohm resistor in series and a 10k pull down (no mosfet driver), the voltage level can be at 5v or 3.3v (
haven't decided yet, mosfet must work with both) at switching frequency of less than 1 kHz. I need to use a lot of these mosfet's on single board each with individual PWM signal, all parts on the board are automotive grade so these mosfet must be AEC-Q101 qualified. I am making a prototype board so I need something that I can hand solder so I choose SOT-23-3 package size.
Note :- I will be using potting epoxy on my boards, so there will be no airflow to these mosfets. I used ambient temperature of 85°C for calculations, these tiny boards will sit behind the taillights.
Summing up mosfet requirements :-
1. Can handle guaranteed 12v 300mA load. (3.6 watt)
2. Should be logic level, fully turns on at 3V.
3. Can handle switching losses at 1 kHz, no mosfet driver required.
4. Automotive grade AEC-Q101.
5. SOT-23-3 package.
I don't know what Rds on value I am looking at for these mosfet's since there is no airflow, I have no idea how would I calculate the power dissipation of the mosfet.
With my limited knowledge I went to mouser and started narrowing down with the above requirements :-
There were 133 results left and at last I sorted them with lowest Rds On and this mosfet comes up at the top.
Nexperia PMV15ENEAR
https://www.mouser.in/ProductDetail/Nexperia/PMV15ENEAR?qs=T3oQrply3y80fkWq77yzJw%3D%3DI attached the datasheet.
Considering my load, is this mosfet okay? What current level can this handle?
Thank you for your time.