Fully Coupled Magnetic Device

The present invention relates to the technical field of coupled inductors, in particular discloses a fully coupled magnetic device, including at least two phases of circuits, with each phase formed by several coupling units connected in series. Every two phases of circuits are directly coupled through at least one coupling unit, and a direction of a magnetic field generated by DC (direct current) of one phase of the two phases of circuits is opposite to that of another phase of the two phases of circuits. The fully coupled magnetic device of the present invention provides direct coupling between any two phases of circuits, which facilitates lower phase current ripple. It has excellent scalability with the highly regular device layout. It is small in size, low in cost, and highly integrated. The device is able to be integrated into a single chip by stacking itself on top of other semiconductor chips. It is also able to be directly built on top of power management integrated circuits (IC) fabricated in advance on a silicon wafer, thereby forming a monolithically integrated power supply, a miniaturized solution with no need of external magnetic devices. The resulting integrated power supplies are able to be applied to replace the traditional discrete-component-based power solutions in a variety of applications.