Traditional distributed-power architectures employ several isolated DC-DC power modules to convert a 48V bus voltage to system supply-voltage rails such as 5V, 3.3V, and 2.5V. That configuration, however, poses difficulties in meeting the load requirements of fast, low-voltage processors, DSPs, ASICs, and DDR memories. Such devices impose stringent requirements on the power supply: very fast transient response, high efficiency, lower voltage rails, and a reduced footprint area. ……