Session
Swifty Session 2
Location
Utah State University, Logan, UT
Abstract
To support the development of the upcoming Binar Space Program 12U Explorer Class platform, currently being designed for lunar and interplanetary research applications, the design and testing of a modular Gallium Nitride (GaN) based Point of Load (PoL) converter is being undertaken. The converter has been designed to supply power to high-transient-current loads, such as communications systems, by regulating down a higher voltage derived from a range of common CubeSat battery configurations to a target voltage of 5V. The system consists of parallel-connected linear regulator and buck converter stages which deliver power to the load through a high-side current sense circuit. The current sense resistor has a fault tolerant current-to-voltage conversion stage followed by a hysteretic comparison trigger stage, feeding a majority-voter subsystem. The output from the majority voter is used as feedback to automatically enable the normally isolated buck converter when a high load current condition is detected at the output. The majority voter, power switches, linear regulator and Buck converter have been implemented using Gallium Nitride High Electron Mobility Transistors (GaN HEMT). Gallium nitride has been selected to take advantage of the high power density and ionizing radiation tolerance intrinsic to the technology.
Design and Testing of a Resilient COTS Point of Load Converter for Deep Space CubeSats
Utah State University, Logan, UT
To support the development of the upcoming Binar Space Program 12U Explorer Class platform, currently being designed for lunar and interplanetary research applications, the design and testing of a modular Gallium Nitride (GaN) based Point of Load (PoL) converter is being undertaken. The converter has been designed to supply power to high-transient-current loads, such as communications systems, by regulating down a higher voltage derived from a range of common CubeSat battery configurations to a target voltage of 5V. The system consists of parallel-connected linear regulator and buck converter stages which deliver power to the load through a high-side current sense circuit. The current sense resistor has a fault tolerant current-to-voltage conversion stage followed by a hysteretic comparison trigger stage, feeding a majority-voter subsystem. The output from the majority voter is used as feedback to automatically enable the normally isolated buck converter when a high load current condition is detected at the output. The majority voter, power switches, linear regulator and Buck converter have been implemented using Gallium Nitride High Electron Mobility Transistors (GaN HEMT). Gallium nitride has been selected to take advantage of the high power density and ionizing radiation tolerance intrinsic to the technology.
