Power transistors and diodes
Power transistors and diodes are the workhorses of the semiconductor industry: Without them, you cannot move or transform any significant amount of electrical energy. The servers populating enormous data farms, white goods with their newly efficient motors, hybrid-electric cars, and home theaters rely on power transistors and diodes that switch and manage their power requirements.
By Margery Conner, Technical Editor -- EDN, October 22, 2009
Power transistors and diodes are the workhorses of the semiconductor industry: Without them, you cannot move or transform any significant amount of electrical energy. The servers populating enormous data farms, white goods with their newly efficient motors, hybrid-electric cars, and home theaters rely on power transistors and diodes that switch and manage their power requirements.
Steve Ohr, research director for analog and power semiconductors at Gartner, points out the “marriage” between power-management ICs and power transistors in high-current applications, such as the point-of-load supplies for server farms. “You don’t get 85 or 90% energy-transfer efficiency without carefully matching the switching characteristics of your switching regulators to the turn-on and turn-off capabilities of your transistors,” he says. “Fractions of a second can 'save the world,’ environmentally speaking.”
There wasn’t much change in the top power-diode vendors in 2008 (Table 1), but the top power-transistor vendors saw some shuffling (Table 2). According to Ohr, it is easy to account for the fact that Infineon and Fairchild traded places: Infineon opened its new 100,000-foot MOSFET facility in Malaysia and has been competitive in the market for 20 to 30V MOSFETs that find use in dc/dc converters. Both Toshiba and International Rectifier also address that market, but Mitsubishi is coming on strong in high-voltage IGBTs (insulated-gate bipolar transistors), which will support hybrid-electric vehicles and electrical power-transmission products.
Continuing down the list, there’s even more activity. Vishay, On Semiconductor, and STMicroelectronics are all competing for the Intel PC VRM (voltage-regulator-module) market, a big user of power transistors that took hard hits in the third and fourth quarters of 2008. In addition, STMicroelectronics was caught in the recession’s downward draft affecting PCs and consumer electronics in the second half of 2008.
