Two novel soft-switched, high frequency, high-efficiency, non-isolated Voltage Regulators-the phase-shift buck converter and the matrix-transformer phase-buck converter

Microprocessors in today's computers continue to get faster and more powerful. From the Intel 80/spl times/86 series to today's Pentium IV, CPUs have greatly improved the performance. Accordingly, their power consumption has increased dramatically , . To reduce the power loss, an evolution began when the high-performance Pentium processor was driven by a nonstandard, less-than-5-V power supply, instead of drawing its power from the 5-V plane on the system board. In order to provide the power as quickly as possible, the voltage regulator (VR), a dedicated dc-dc converter, is placed in close proximity to power the processor. In the beginning, VRs drew power from the 5-V output of the silver box. As the power delivered through the VR increased so dramatically, it became no longer efficient to use the 5-V bus. Then for desktop and workstation applications, the VR input voltage moved to the 12-V output of the silver box. This trend began when Pentium II processors emerged. Today's Pentium IV processors use 12-V-input VRs.