Phase-Shifted Converter for Distributed Power Supply

The last generation of microprocessors, recently introduced, has shown an increase in the operating frequency and, of course, in the supply characteristics. The different need of power makes necessary a severe design for the traditional isolated topology and push towards converters more suitable to meet the new high efficiency and high power exigencies. The paper proposes a solution for distributing power in computing systems (high performance PCs and servers) based upon a DC to DC phase-shifted converter switching at 500kHz. It is characterized by a disposition in line of the MOSFETs and good soft switching performances. The converter acts as a charge generator controlled period by period. The operating principles of the SILC are described in the paper and the steady state behaviour is represented. Its small signal model has a first order dynamics, well suited for active loads, for instance low-voltage, high-current point-of-load converters. The characterisations make reference to a 800W distributed power architecture. Efficiency forecasts, neglecting the losses of the point-of-load converters and of current limiters are above 90% at full load and remain high until the load falls below one third of full load