A New Kind Of Transistor

I just read an interesting article in NASA Techbriefs about a new kind of transistor called a Not Majority gate. It has three inputs and puts out a true signal if true inputs are not in the majority. In ordinary logic majority gates are not simple. A majority gate would take 32 transistors to make in conventional CMOS logic. A single transistor majority gate would greatly simplify the logic of a full adder by taking advantage of the ability of a majority gate to change from NAND to NOR logic by changing one input. The full adder in CMOS logic would take about twice as many gates and four times as many transistors vs. majority gate logic. Here is a nice explanation of Majority Gate transistor works, with an idealized view of how one is constructed.

Now all this is kind of esoteric (unless you are a bit head) so what is the good of it? It has the potential of shrinking and speeding up the logic part of microprocessors. A small advance (most silicon area these days is devoted to memory of one sort or another), but it will help. In addition it will help a lot in power consumption. With fewer gates switching for a given function, power losses will be lower.

If you are in a particularly geeky mood I have a nice article on High Frequency Transimpedance Amplifiers up at IEC Fusion Technology.