Payload protection on CubeSat based on GaN Power Transistor

Latching Current Limiter (LCL) is used in satellites to protect payloads. A CMOS power transistor is commonly used as a switching device in these types of circuits. The LCL limits the current under short-circuit conditions, isolates the fault to maintain the safety of the Electrical Power System (EPS). Nevertheless, its functionality can be lost due to the effects of radiation present in space. This condition can compromise the operation of the satellite. To improve radiation tolerance, Gallium Nitride (GaN) transistor can be used as the switching device because it has more radiation hardness than silicon transistors. In this work, two LCLs implemented with GaN transistors and with integrated control loop in 0.18μm CMOS technology are presented. The control loops were implemented with Low Voltage (LV) devices that support up to 3.3 V. LCLs have limitation current and trip-off time as adjustable protection parameters. Validation tests were carried out on circuit prototypes under short-circuit conditions, for different supply voltages. The LCLs presented a response time of less than 10μs and worked correctly in all the tests carried out.