In recent years, the space market has been driving towards more efficient power management solutions. Part of the drive includes the use of Gallium Nitride (GaN) FETs as power stages. GaN FETs have higher power conversion efficiency and have more natural immunity to radiation, due to them being wide-bandgap semiconductors. Renesas has developed a radiation hardened 100V GaN FET + integrated low-side driver to efficiently drive the GaN FETs used in these power systems. These plastic-packaged, radiation hardened GaN FET + drivers are used for DC/DC power supplies in many different mission types.