A closer look to the factors affecting the switching transient times of optocouplers.

The significant parameters for a high-speed optoelectronic switch were the transient times. In the time domain, there is a time elapsed on the order of microseconds between applying a current pulse and seeing an output. Therefore, the present work aimed to give a closer look on the factors affecting the transient times of the optocoupler switching action, namely; delay (td)-, rise (tr)-, in addition to storage (ts)- and fall (tf)-times. The turn-on time (Ton = td + tr) and turn-off time (Toff = ts + tf) of the optocoupler (type 4N25) were investigated and plotted under the influence of different operating conditions such as: load resistance (RL), forward LED drive current (IF), bias collector voltage (VCC), emitter–base resistance (RBE), and ambient temperature. [ABSTRACT FROM AUTHOR]