I am using IRLZ44 to power 12V RGB LED strip with an ESP8266. It is 3.3V logic, so the focus is on the logic level. It could be any 3.3V Arduino.
In the datasheet, it says min logic level on Gate is 4V, on ESP8266 I have 3.3V. Anyway, I closed my eyes and pulled the switch. And it works! Works for hours without any issue.
My questions are:
No matter it works, the datasheet says different. Should I use some other MOSFET?
As it works, do you suggest just adding some transistor (8050, 2222) on the logic line?
Or should I just leave it as it is, and move on?
While it is not useful to consider just the threshold voltage - which for this device is specified at no more than 2.0 V, the 4.0 V specified is for a RDS(on) value of no more than 39 mΩ. At 3.3 V it will be not a great deal more and the device clearly is a very practical switch at this voltage for several Amps without a heatsink.
In fact, figure 2 in the datasheet suggests that at 3 V on the gate you should expect it to happily pass 3 Amps with only 600 mW dissipation requiring little or no heatsink.
The chart in the datasheet shows the current limit with 3.3V on the Gate is about 30A. The colors may not have equal current draw so you probably can't assume that the 3A draw with all on means 1A on each color. Let's say the worst color draws 2A for 5 meters. That would mean you could drive 15 times as many lights (30A/2A) or 75 meters.