Latching Current Limiter SEE Susceptibility from Heavy Ions

Current Limiting Switches, often referred to as Latching Current Limiters (LCL), find extensive application in the aerospace industry. These devices are crucial for safeguarding the DC power bus, providing timed responses, controlled inrush currents, and limited overcurrent to prevent potentially hazardous overloads and surge currents. Moreover, LCLs offer the capability to restart loads that have experienced temporary failures.However, when using LCLs in challenging environments, particularly in aerospace and space applications, radiation effects on their electronics become a significant concern. To mitigate these effects, a range of design techniques must be employed to ensure the reliable operation of LCLs.This study presents the implementation and testing of two distinct LCLs, each utilizing different controllers. The first controller circuit employs microelectronics specifically designed for the purpose, constructed using SOI 0.6μm technology. The second circuit also utilizes microelectronics custom-designed for the application incorporating radiation hardening by design (RHBD) techniques, using SOI 0.6μm technology. Both LCLs employ the same model of current sensor and a P-channel power MOSFET.To assess their performance in the space environment, the LCLs were subjected to radiation tests using heavy ions as part of the Single Event Effects (SEE) analysis. Ions, including protons, oxygen (O), chlorine (Cl), and copper (Cu), were employed at different energy levels and flux rates. The study presents the test results for both LCL designs, highlighting the observed differences in their behavior during radiation exposure. The tests revealed the occurrence of total ionizing dose effects on the circuits.