A buck-boost switching converter includes a soft-switching circuit coupled across
the boost switch, controlled to establish a short-circuit across the boost switch
prior to turn-on of the boost switch. The converter also includes a second soft-switching
circuit including a third switch and a saturable inductor coupled across the buck
switch. The third switch is rendered conductive sufficiently before the buck switch
so that a half-cycle of resonance can occur between the saturable inductor and
the buck switch.
