An fully integrated DC-to-DC switching converter having an inductor, where the inductor has magnetic material that may be amorphous CoZrTa, CoFeHfO, CoAlO, FeSiO, CoFeAlO, CoNbTa, CoZr, and other amorphous cobalt alloys. The magnetic material allows for a relatively high switching frequency. In one embodiment, the inductor has two sub-structures, where each of the two sub-structures are parallel to each other and each includes a conductor having upper and lower portions. The conductors of the two sub-structures are electrically connected to each other, and the upper and lower portions are arranged so that magnetic flux from one of the sub-structures couples with the magnetic flux from the other sub-structure so as to provide a relatively high inductance with small form factor. In another embodiment, the inductor is a simple conductor surrounded by high-frequency magnetic material. In both structures, oxide insulates the conductors from the magnetic material.