Radiation induced degradation analysisand reliability modeling of COTS ADCs for space-borne miniaturefiber-optic gyroscopes

Respecting the requirements of light weight, small size, low power consumption and especially low cost, commercial off-the-shelf (COTS) analog-to-digital converters (ADCs) are gradually being used to replace specifically designed aerospace-grade ones in space-borne miniature interferometric fiber-optic gyroscopes (IFOGs). However, the total ionizing dose (TID) effect of γ-ray radiation in the space environment may cause the damage of COTS ADCs and lead to performance degradation even failure. In order to measure the safety of COTS ADCs in IFOGs under the TID effect, the radiation induced degradation model and the corresponding reliability model are proposed in this work. First of all, the relationship between the degradation of COTS ADCs and the IFOG’s angular random walk (ARW) is deduced. Then, a radiation accelerated test is designed and performed, with a real-time, dynamic data acquisition method based on the first-input-first-output memories to determine the degradation of COTS ADCs. Finally, a degradation path model is established based on the degradation data and the reliability of COTS ADCs used for space-borne IFOGs is further obtained by using the Monte Carlo method. An engineering application is introduced to show the effectiveness of the proposed model and the results show that the reliability of the experimental COTS ADCs makes them usable for the space-borne miniature IFOGs in low-earth orbit and geostationary earth orbit space missions.