GaN Power Switch for Power Distribution Protection

The electrical power system (EPS) of satellites requires protection devices to isolate failures in short-circuit conditions that can occur in payloads due to various sources, such as debris, mishandling, or radiation. Latching current limiter (LCL) implemented with a pMOS power transistor is typically used for this task. Radiation can also affect the function of the LCL and compromise the mission of the satellite. Therefore, to improve radiation hardness, LCLs have been developed using different rad-hard techniques, such as the implementation of Wide BandGap (WBG) semiconductors as power switches. Gallium nitride (GaN) transistors are more resistant to radiation due to their intrinsic characteristics. In this letter, an LCL topology with a GaN power switch is presented to improve system reliability for space applications. The LCL has an integrated control circuit in 0.18 $\mu \text{m}$ CMOS technology powered by an auxiliary source. The proposed LCL was validated by simulation and experimental tests. The LCL limited the current to the set value for a supply voltage of up to 50V and maintained a recovery time of less than 50 $\mu \text{s}$ , under short-circuit tests.