Low profile, low cost, new geometry integrated inductors

A new geometry of integrated inductors with low profile and low cost is presented in this paper. The new geometry integrates two inductors by stacking three I-cores. The middle I-core provides a shared low reluctance flux path. The air gaps are formed by separating the I-cores using copper foil windings with well-defined thickness. Many advantages and disadvantages are described in depth. In this work, inverse coupling and direct coupling in the new geometry integrated inductors have been analyzed. Coupling characteristic caused by a special saturation behavior has been emphasis. And also variable inductors caused by the special saturation behavior may be utilized in some applications. The new integrated inductors make it possible to build low-profile, low-cost, flexibility DC/DC converters, and it can be extensively designed for the low-voltage and high-current required by the modern digital applications. Experiment results obtained from a 48V-12V 30A two-phase interleaved bidirectional DC/DC converter, demonstrates the characteristic of new geometry and difference between inverse coupling and direct coupling.