Hi, I want to switch a couple of 5V devices with my Arduino and do not want to draw too much current from the mc itself. Therefore, I purchased 2n7000 mosfets as they are rated to work well at logic level voltages (according to the datasheet , the V_GS threshold where they start conducting is typically at about 2.1V -- furthermore, at 5V between GS and DS, they are theoretically supposed to provide about 500ma, i.e. the transistor resistance should imho be negligible - R_DSon should be well below 5ohm).
However, when using a simple setup connecting 300 ohm resistance as load, supplying the FET with 5V and turning it "on" with 5V at the gate, the transistor drops about 2V. This is getting worse when I decrease the resistance. Whereas, putting higher voltages on the gate turns the transistor rather rapidy fully on beginning with about 6,5V. I also did try other transistors of this charge, so this is at least not a single bad apple.
What am I possibly missing here? What are alternatives to the 2n7000 model (I appreciate the TO-92 form factor)? Do you think a simple level conversion pulling the arduino outputs up to 12V would be a suitable solution?
Many thanks in advance.