New packaging solutions and power module structures are required to fully utilize the benefits of emerging commercially available wide bandgap semiconductor devices. Conventional packaging solutions for power levels of a few kilowatt are bulky, meaning important gate driver and measurement circuitry are not properly integrated. This paper presents a fast-switching integrated power module based on gallium nitride enhancement-mode high-electron-mobility transistors, which is easier to manufacture compared with other hybrid structures. The structure of the proposed power module is presented, and the design of its gate driver circuit and board layout structure is discussed. The thermal characteristics of the designed power module are evaluated using COMSOL Multiphysics. An ANSYS Q3D Extractor is used to extract the parasitics of the designed power module, and is included in simulation models of various complexities. The simulation model includes the SPICE model of the gallium nitride devices, and parasitics of components are included by experimentally characterizing them up to 2 GHz. Finally, the designed power module is tested experimentally, and its switching characteristics cohere with the results of the simulation model. The experimental results show a maximum achieved switching transient of 64 V/ns and verify the power loop inductance of 2.65 nH.