GaN's properties of low Coss, Crss, and lack of reverse recovery make it a more efficient power switch versus silicon. These characteristics enable higher-frequency hard-switched topologies such as totem-pole bridgeless power factor converter (PFC) that cannot be realized by silicon MOSFETs and insulated-gate bipolar transistors (IGBTs) due to their high switching losses. To take advantages of these properties, GaN must be switched quickly and reliably. This paper examines requirements for the driver, package, and the GaN HEMT to enable efficient and reliable switching.