EEVblog Electronics Community Forum

EEVblog => EEVblog Specific => Suggestions => Topic started by: kurohyou on July 31, 2012, 08:36:49 pm

Title: Episode about mosfets
Post by: kurohyou on July 31, 2012, 08:36:49 pm
Hi Dave,

i would like to see an episode about mosfets :

- How do you choose on the distributors website which one to get. (For what to watch out for)
- A little explanation how to read the data sheets
- logic level fet's, how to use them directly from the micro-controller, not 1 but for example 10 logic level fet's on 1 micro, precautions to take, capacitors to use so we have enough current to drive the micro.
-  Non logic level fet's driving directly from the micro controller.

I had a problem a month ago, i was driving 10 p channel mosfets (NDT2955) from an atmega32, i had a resistor between the the gates (120 Ohm). I was driving common anode rows of rgb led at a fast rate. The problem was that the micro was constantly rebooting, after a check on the oscilloscope i  saw i had some major spikes on the voltage of the micro. So i added a 470 nF MKT cap on the micro. No problems so far. But i don't think this is the best solution longterm.

After some searching on different forums it was like nobody had some real solutions, check digikey, check the data sheet, check google. All great propositions but no real answer. So i guess i'm not the only one that had a difficulty here with this.

greets, love the show.