There is disclosed a core structure with a very low profile, high power density
and lower losses. The disclosed design allows for a larger core area where the
DC fluxes are added, thereby reducing the air-gap requirements in the cores derived
from low saturation density materials such as ferrites. The cellular nature of
the design can be effectively employed in vertically packaged power converters
and modules. Also disclosed is a DC-DC converter topology which preferably employs
the disclosed core. N AC drive voltages drive N current doubler rectifiers (CDRs)
in accordance with the symmetric modulation scheme; each CDR provides two rectified
output currents to an output node. Each AC drive voltage has a switching period
Ts. The drive voltages are phase-shifted by Ts/(2*N), such
that the rectified output currents of the CDRs are interleaved, thereby reducing
output voltage ripple.
