Inductor devices and stacked power supply topologies

1. An inductor device comprising:

a core fabricated from magnetically permeable material, the core including an inner diameter and an outer diameter, the magnetically permeable material disposed between the inner diameter and the outer diameter;

an electrically conductive path disposed within the inner diameter of the core, an outer diameter of the electrically conductive path extending to the inner diameter of the core;

a magnetic permeability of the core varying in magnitude depending on a distance with respect to the electrically conductive path;

wherein the core includes multiple concentric layers of magnetically permeable material disposed about the electrically conductive path;

wherein the multiple concentric layers of magnetically permeable material include a first concentric layer of magnetically permeable material and a second concentric layer of magnetically permeable material;

wherein the first concentric layer of magnetically permeable material extends between the outer diameter of the electrically conductive path to an inner diameter of the second magnetically permeable material; and

wherein a portion of the second concentric layer of magnetically permeable material disposed near the inner diameter of the second concentric layer of magnetically permeable material is operative to support a first magnetic flux density, the first magnetic flux density being greater than 50 percent of a second magnetic flux density supported by a portion of the first concentric layer of magnetically permeable material disposed near an inner diameter of the first concentric layer of magnetically permeable material.

2. The inductor device as in claim 1 , wherein the magnetic permeability of the core varies as a function of a radial distance from the electrically conductive path.

3. The inductor device as in claim 2 , wherein the magnetic permeability of the core increases in magnitude as the radial distance from the electrically conductive path increases.

4. The inductor device as in claim 1 , wherein the core includes multiple concentric layers of material with respect to the electrically conductive path.

5. The inductor device as in claim 1 , wherein the core is operative to confine magnetic flux generated from current flowing through the electrically conductive path.

6. The inductor device as in claim 1 , wherein a magnitude of the magnetic permeability of the magnetically permeable material is between 30 and 150 Henries/meter.

7. The inductor device as in claim 1 , wherein a change in the magnetic permeability in the core as a function of the distance from the electrically conductive path is substantially linear.

8. The inductor device as in claim 1 , wherein a change in the magnetic permeability in the core from the inner diameter of the core to an outer diameter of the core is linear.

9. The inductor device as in claim 8 , wherein the change is stepwise linear in accordance with a stepwise linear function, each step in the stepwise linear function corresponding to a different magnitude of a respective magnetically permeable material layer between the inner diameter of the core to the outer diameter of the core.

10. The inductor device as in claim 8 , wherein the change is a continuous linear gradient in accordance with a linear function.

11. The inductor device as in claim 1 , wherein the electrically conductive path is a first electrically conductive path.

12. The inductor device as in claim 11 , wherein the second concentric layer of magnetically permeable material has a higher magnitude of magnetic permeability than the first concentric layer of magnetically permeable material.

13. The inductor device as in claim 12 further comprising:

a second electrically conductive path encompassing the core of magnetically permeable material.

14. The inductor device as in claim 13 , wherein the second electrically conductive path is disposed circumferentially as a layer of material disposed at the outer diameter of the core.