Introducing DMOS power FETs

introduein MOS power nits The term VFET will sound familiar to most readers, although few are likely to have actually seen one "in the flesh". Not that they are much to look at, but it does go to show that VFETs have as yet failed to attract the amount of popu- larity they deserve. Way back in 1976 (see the Elektor April issue of that year) VFETs were billed to be the (almost) ideal output transistors for (audio) amplifiers. Due to their high price and poor availability, however, they never quite made it into the limelight. But then, this is just one of those vicious circles, for components don"t drop in price and become easy to obtain until they are already popular ... About a year ago, a new branch was welcomed to the VFET family: the DMOS series. Basically, they are very similar in operation to VFETs, but their structure is slightly different and their switching times are much faster. DMOS FETs are in fact mainly promoted as fast switches. They are predicted to take over a larg...