Radiation characterization and test methodology study of optocouplers devices for space applications

This work investigates the degradation of several different optocouplers for space applications. Hardened and standard (unhardened) types are tested under proton, neutron and Co/sup 60/ irradiations under various bias, fluence and dose rate conditions. An attempt to define an industrial cost-effective test procedure is proposed.

I. Introduction

Optocouplers, or optoisolators, are widely used in space applications where particles such as protons are of primary concern. But these devices are known to be strongly degraded under proton irradiations which generate both displacement damage and total ionizing dose (TID) [1], –[3], [5], [6]. Indeed, optocouplers consist of a LED (AlGaAs or GaAs), often highly susceptible to displacement damage, and of a silicon phototransistor (or a couple silicon photodiode and transistor) affected by both effects.