HI, I have a doubt to use the p-channel mosfet irf9540n with led’s.
what I want to do is to use the irf9540n to control a maximum of 64 leds(20mA each) at the same time where leds are connected in parallel like photo.
when I do 5V from arduino pin the mosfet is turn OFF instead when I do 0V from arduino pin the mosfet is ON and leds turn ON
(the resistor 10k is a pull up resistor only useful to take mosfet off when for example arduino resetting ).
my problem is that IRF9540n have a Vth from 2 to 4 so can the mosfet work wrong in this configuration especially when i use red leds because their Vled is ~2.2V?
can anyone tell me an name of mosfet p-channel with a Vth lower than the IRF9540n but dimensioned with the current necessary for all LEDs (so 20mA x 64 = 1,28 A than 1,28A x 5V = 6,4 W)?