Transformer-driven power switch devices are provided for switching high currents. These devices include power switches, such as Gallium Nitride (GaN) transistors. Transformers are used to transfer both control timing and power for controlling the power switches. These transformers may be coreless, such that they may be integrated within a silicon die. Rectifiers, pulldown control circuitry, and related are preferably integrated in the same die as a power switch, e.g., in a GaN die, such that a transformer-driven switch device is entirely comprised on a silicon die and a GaN die, and does not necessarily require a (large) cored transformer, auxiliary power supplies, or level shifting circuitry.