Even though we publish new blogs daily from your intrepid editor and from a number of well-known writers, sometimes it's good to have a look back at some of our well received articles from the recent past. Here is one that ties in with my recent blog that discussed IGBTs and MOSFETs.
The article was written by Linden Harrison, at the time a technical writer for Advanced Linear Devices Inc. Linden briefly discusses the enhancement-mode MOSFET. In the case of an N-channel device, that's the version whereby you apply a positive voltage to the gate with respect to the source to enhance the conduction channel (turn it on).
The author then dives in to the depletion-mode devices, which work the other way: It's already on, and you apply a negative voltage to the gate to turn it off.
This is a solid article with plenty of good information on theory and with practical applications.