Vishay Intertechnology (Malvern, PA) recently announced its power MOSFET chip set designed to improve the efficiency of dc/dc conversion circuits in notebook PCs. According to the company, the new chip set works with popular controller ICs from Vishay to deliver improvements in efficiency on the order of five percent compared with previous power MOSFET devices. The chip set consists of the Si4874DY, a 7.5 milliohms device with 35nC gate charge, and the Si4884DY, a 10.5 ohms device with 15.3nC gate charge. The Si4874DY is designed to provide the low on-resistance required for the bottom freewheeling MOSFET, which carries the current for the majority of the time, and is designed to withstand fast switching transients. For the upper MOSFET slot in the same circuit, the Si4884DY provides the fast switching times that are critical for the switching FET role. According to Vishay, in a converter with a 15A output and a Vout of 2V, the chip set delivers 83 percent efficiency, and 95 percent at 3A. Pricing in quantities of 100,000 starts at $0.71 each. Sample and production quantities are currently available.