开展了4N49光电耦合器不同辐照偏置条件下的辐照实验,结果表明:电流传输比的下降幅度与辐照期间的偏置条件有关,处于工作状态的光电耦合器比短路状态的总剂量效应要弱,其根源是光电耦合器的LED施加了电流,而与光敏晶体管的偏置状态关系不大;电流传输比随偏置条件的变化关系是由初级光电流决定的,而C-B区光响应度是初级光电流退化的主导因素。 The experiment of 4N49 photocoupler under different irradiation bias conditions was carried out. The results show that the drop of current transfer ratio is related to the bias condition during irradiation. The effect is weaker, the root cause is that the optocoupler LED current is applied, and the photosensitive transistor bias state is not; current transfer ratio with the bias condition is determined by the primary photocurrent, and CB area light Responsiveness is the dominant factor in the degradation of primary photocurrent.