A matrix transformer particularly suited to large voltage step-down, high current applications achieves increased good current sharing uniformity or air gap and electrical characteristics and reduced or eliminating termination losses, core losses and winding losses with a unitary magnetic core structure featuring sheets of magnetic material and a two-dimensional array of pillars on which windings, oriented in opposite directions on pillars that are adjacent in orthogonal directions, can be formed or placed comprising metallization on or embedded in a printed circuit board (PCB) structure. Magnetic flux density is reduced by at least one-half by dividing the magnetic flux in each pillar into two paths of increased width in the sheets of magnetic material. Magnetic flux density may be further decreased and flux uniformity improved by extending the sheets of magnetic material beyond a periphery defined by the pillar array.