TID Level of Failure Dependence From Operating Configuration of the System—Space Class DC/DC Converter Case Study

We present and analyze system-level total ionizing dose (TID) tests of the simple analog system, point-of-load (PoL) dc/dc converter from 3D Plus, which was already qualified up to 50 krad(SiO2) based on component-level tests. TID response varied with the radiation facility for several parts; however, extensive testing with one part has shown significant differences in the TID level of functional failure observed for different operation modes (configurations): depending on the operating configuration of the device, the observed TID level of failure varies from about 60 krad(SiO2) to more than 400 krad(SiO2). These differences are depicted with the use of the safe operating area (SOA) plot for the system, which incorporates main system functional parameters. We also explore the potential utilization of the SOA concept in defining the system’s TID performance, employing a range of TID thresholds rather than relying on a singular value.