High current inductor design for MHz switching

High current inductor applications operating in the MHz range are generally limited to Voltage Regulator Modules (VRM’s) and Point of Load (POL) power supplies, where the issue of fast transient response demands reduced inductance values. State-of-the-art controller IC’s enable switching frequencies up to 8 MHz for low current POL applications. However, for current levels higher than 1 A, commercial inductors are not generally quoted as suitable for operation beyond 5 MHz. The application of electroplated metal alloy foils to produce competitive discrete cores suitable for operation in the range of 1 – 5 MHz is investigated in this paper.