US Patent 10128035 Coupled inductor arrays and associated methods

A coupled inductor array includes a monolithic magnetic core formed of magnetic materials having a distributed gap, first and second windings, and a low-permeability magnetic structure. The first and second windings form respective first and second winding turns around a common winding axis extending in the height direction. The low-permeability magnetic structure is embedded in the monolithic magnetic core and forms a loop around the common winding axis. The low-permeability magnetic structure separates the first and second winding turns in the height direction, and the low-permeability magnetic structure is formed of a magnetic material having a lower magnetic permeability than the one or more magnetic materials forming the monolithic magnetic core. One possible application of the coupled inductor array is in a multi-phase switching power converter.