Dual-coiled transformer inductor

A transformer inductor, comprising:

• a first conductive coil;
• a second conductive coil positioned concentrically with respect to the first conductive coil;
• a dielectric positioned between the first and second conductive coils;
• a composite magnetic core comprising a first magnetic material having hard saturation characteristics and a second magnetic material having soft saturation characteristics, wherein the composite magnetic core at least partially encases the first and second conductive coils;
• and
• an air gap positioned within the first magnetic material,
• wherein the first and second conductive coils are configured to provide variable magnetic coupling based on current levels flowing through the coils.

A transformer inductor for mobile device voltage regulation, comprising:

• an outer coil structure;
• an inner coil structure positioned concentrically within the outer coil structure;
• a micro-thin dielectric layer separating the outer coil structure from the inner coil structure;
• and
• a molded magnetic material encapsulating the outer coil structure, the inner coil structure, and the micro-thin dielectric layer to form a low-profile package having a height below 3 mm,
• wherein the inner coil structure is positioned concentrically with respect to the outer coil structure to form a concentric arrangement and provide a coupling coefficient approaching unity while maintaining electrical isolation through the micro-thin dielectric layer.