Abstract: Integrated circuits, wafer level integrated III-V power device and CMOS driver device packages, and methods for fabricating products with integrated III-V power devices and silicon-based driver devices are provided. In an embodiment, a boost converter circuit includes an inductor; a power switch having a conducting state and blocking state; and a control circuit for controlling the power switch from the conducting state to the blocking state for controlling flow of the current in the inductor, wherein the control circuit comprises a silicon integrated circuit comprising bipolar CMOS transistors, wherein when the power switch comprises a first GaN transistor, and wherein the power switch and silicon integrated circuit are electrically and mechanically coupled by way of flip chip bonding.