Vin = 2.0V and Conclusion
For power MOSFET IRL540N, the channel seems to almost completely closed at Vin ~= Vgs ~= 2V.
At Vgs = 5V, 12V 5R 1kHz 50% duty cycle, rms current = 850 mA, dropping to about 800mA at Vgs = 4V, 3V.
My quick and dirty conclusion (based on one and only one sample ) is that IRL540N works with Rpi GPIO 3V if and only if the resistive loading is 800 mA rms.
Since the unofficial spec of Rpi GPIO is Voh > (2.4V ~ 2.8V). It is unreliable to use Rpi GPIO signal directly on IRL540N. A logical level shifter such as EL817C or TSX0102/4/8 to convert 3.3V logic to 5V is more reliable.
I am only using ICL8038 sig gen to simulate Rpi GPIO signal.
Next step is to use the real thing, Rpi to do the testing.
- vin_2v0_2019feb2801.jpg (194.89 KiB) Viewed 451 times
I am an electronics and smart home hobbyist.