In an attempt to switch some 12V LED strips from my 3.3V microcontroller, I bought some IRLZ44N FETs off eBay, hoping to directly switch them on 3.3V. Maybe eBay was a bad call
Datasheet:
http://www.irf.com/product-info/datasheets/data/irlz44n.pdf It seems to claim that 3.3V is enough to saturate the FET in order to deliver the 1A required for the LED strip.
In my original test circuit, I connected the micro's 3.3V port output through 100Ohm onto the gate, a 100k pulldown on the gate, source directly onto ground, and drain directly onto "-" of the LED strip. "+" of the LED strip goes to +12V.
In 7 out of 10 FETs, only very little current flows (about 1 mA). In the 3 others, I get 0.7A, close enough to light up the strip fully.
If I increase the gate voltage to 6V, all FETs switch on fully.
Removing the pulldown and gate resistors has no effect.
What could be going on here? Are the FETs damaged, mislabeled, or am I misunderstanding the datasheet completely?
Any help will be greatly appreciated.