Emerging optocoupler issues with energetic particle-induced transients and permanent radiation degradation

Radiation-induced permanent degradation and single event transient effects for optocouplers are discussed in this paper. These two effects are independent to the first order and will be addressed separately. Displacement damage-induced degradation of optocoupler current transfer ratio is reviewed. New data are presented that show the importance of application specific testing and that generalized quantification of optocoupler CTR degradation can lead to incorrect predictions of actual circuit performance in a radiation environment. Data are given for various circuit loading and drive current parameters. Previous work that introduces the idea that two mechanisms exist for inducing transients on the optocoupler output is discussed. New data are presented that extends the evidence of this dual mechanism hypothesis. In this work measurements show that single event transient cross sections and transient propagation varies with circuit filtering. Finally, we discuss utilization of the optocouplers in the space environment. New data are applied to two examples: one on permanent degradation and the other on single event transient rates in high bandwidth applications.