Emerging optocoupler issues with energetic particle-induced transients andpermanent radiation degradation

Radiation-induced permanent degradation and single event transient effects for optocouplers are discussed in this paper. These two effects are indepen dent to the first order and will be addressed separately. Displacement dama ge-induced degradation of optocoupler current transfer ratio is reviewed. N ew data are presented that show the importance of application specific test ing 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 p arameters. Previous work that introduces the idea that two mechanisms exist for inducing transients on the optocoupler output is discussed. New data a re presented that extends the evidence of this dual mechanism hypothesis. I n this work measurements show that single event transient cross sections an d transient propagation varies with circuit filtering. Finally, we discuss utilization of the optocouplers in the space environment. New data are appl ied to two examples: one on permanent degradation and the other on single e vent transient rates in high bandwidth applications.