Multi-stage permanent magnet structure and integrated power inductors

Abstract

Apparatuses and methods directed to multi-stage permanent magnet and implementations of a permanent magnet on-chip power inductor. Various circuit models, design considerations and simulation results are described. The multi-stage permanent magnet includes layers with uniform or non-uniform magnets used to control the flux distribution. The permanent magnet on-chip power converter for DC-DC switching power converters that may include a top ferrite layer, a spiral winding layer, a permanent magnet layer, a bottom ferrite layer, and a substrate layer. The permanent magnet layer may comprise a multi-stage structure wherein each stage has a decreasing area as compared to an immediate lower stage. A method of manufacturing a Permanent On-Chip Power Inductor (PMOI) is also disclosed.

What is claimed is: 
     
         1 . A power inductor for a DC-DC power converter, comprising:
 a magnetic core;   at least one winding wound about the magnetic core; and   a permanent magnet disposed within the magnetic core.   
     
     
         2 . The power inductor of  claim 1 , wherein the magnetic core is formed from a top ferrite layer, a winding layer and a bottom ferrite layer, and wherein the permanent magnet is disposed between the winding layer and the bottom ferrite layer. 
     
     
         3 . The power inductor of  claim 2 , wherein the magnetic core is formed on a substrate. 
     
     
         4 . The power inductor of  claim 1 , wherein the magnetic core is formed as a toroid, and wherein the permanent magnet is disposed in a gap formed in the toroid. 
     
     
         5 . The power inductor of  claim 1 , wherein the permanent magnetic is coupled to the magnetic core having a plurality of legs each having an associated winding, and wherein at least two windings are coupled together. 
     
     
         6 . The power inductor of  claim 1 , wherein the permanent magnetic is uncoupled to the magnetic core. 
     
     
         7 . A magnet, comprising:
 a plurality of magnetic layers arranged as a multi-stage structure,   wherein each stage has a decreasing area as compared to an immediate lower stage.   
     
     
         8 . The magnet of  claim 7 , wherein each stage is formed having a generally square shape. 
     
     
         9 . The magnet of  claim 7 , wherein the permanent magnet layer is generally pyramid-shaped. 
     
     
         10 . The magnet of  claim 7 , wherein the magnet comprises 10 stages. 
     
     
         11 . The magnet of  claim 7 , wherein the magnet has a predetermined magnetic field distribution designed to cancel winding flux. 
     
     
         12 . The magnet of  claim 11 , wherein the magnet is provided in a motor or generator in order to optimize the magnetic field distribution.