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Given the maturity of MOSFETs, selecting one for your next design may seem deceptively simple. Engineers are familiar with the figures of merit on a MOSFET data sheet. Selecting a MOSFET requires the engineer to use their expertise in scrutinizing different specifications for individual applications. In an application such as a load switch in a server power supply, the switching aspects of a MOSFET matter little because the MOSFET is on almost 100% of the time. The on resistance (RDS(ON)) may be the key figure of merit in such an application. Still other applications, including switching power supplies, use MOSFETs as active switches, and cause the engineer to value other MOSFET performance parameters. Let us consider some applications and their prioritization of MOSFET specifications.

The potential for the QTC material to transition from an insulator to a conductor (i.e. change its electrical property) is influenced by how much deformation the material is experiencing as a result of the applied mechanical pressure. QTC can be used to produce low profile, low cost, pressure activated switches or sensors that display variable resistance with applied force and return to a quiescent state when the force is removed. The difference between a QTC switch and a QTC sensor is arguably only the speed and amount of physical input required to achieve the required switching point or resistance range.

Tiny semiconductor dots could lead to a new type of circuit based on magnetism rather than current flow. At least that’s the hope of researchers who’ve made the dots and are hoping to build them into a workable device. ”We want to make it into a so-called nonvolatile transistor,” says Kang Wang, head of the Device Research Laboratory at the University of California, Los Angeles. Such a ”spintronic” transistor would retain its logic state in the absence of current and require less power to switch a bit, reducing the electrical power required by a computer chip by as much as 99 percent. Wang’s research, supported in part by Intel, was published in March in the online version of Nature Materials. Where electronic transistors rely on the presence or absence of current to register the ones and zeros of digital logic, spintronic transistors depend on ”spin,” a quantum characteristic of the electron. Picture the electron as a rotating globe. When the north pole is pointing upward, that’s spin up; when pointing the other way, it’s spin down. When the spins of most electrons are aligned, the material is magnetic. When their spins are random, the material isn’t. An applied current can align or randomize the spins, allowing for spin-based switches.

bowl and pairing off to come up with a way to create and commercialise sensors and switches that generate their own power. The idea is that the parts will make external power sources redundant - because they can convert energy from body heat, light and vibrations straight into electricity. Self powered electronics have already sporadically been used in technology like wall-mount remote control units for air conditioners, says Nikkei, but existing parts are bulky and cost a couple thousand yen a piece. 3,000 yen is about $35 - which means they're not the best bet, financially, yet.

March has seen two significant announcements from FPGA start-ups with innovative architectures: Tabula, with their time-domain-multiplexed architecture, and TierLogic, implementing their routing switches in a layer of thin-film transistors. Both approaches promise to significantly reduce the die size and cost of high-end FPGAs. But before these announcements broke, a relatively unnoticed paper at February's International Symposium on FPGAs described what may be the most radical technology of them all: FPGAs using electromechanical relays. No, this is not an early April Fool's joke, nor is it one of those "let's see if anyone will publish this one" academic exercises. The paper presented work by professors and students at the Stanford University departments of electrical engineering and computer science, and researchers at Altera Corp. The work was supported in part by DARPA funding.

A transistor that emits light and is made from organic materials could lead to cheaper digital displays and fast-switching light sources on computer chips, according to the researchers who built it. Small displays made from diodes of the same type of materials (organic light-emitting diodes, or OLEDs) are already in commercial production, but the transistor design could improve on those and lead to applications where OLEDs can’t go. The new organic light-emitting transistor (OLET) is much more efficient than previous designs. It has an external quantum efficiency—a key measure of how much light comes out per charge carrier pumped in—of 5 percent. An OLED based on the same material has a quantum efficiency of only 2 percent. Previous OLET designs had an efficiency of only 0.6 percent.