The Isocom MOC3020XSM is an optically coupled isolator containing a GaASP LED and an integrated circuit with a zero-crossing triac driver. It is an optocoupler, used to isolate voltage between two circuits. This device has a direct interface with AC loads and provides increased noise immunity and high surge current ratings. The optocoupler provides reinforced over-voltage protection, high input-to-output insulation, and the ability to operate up to 250V RMS. This device is commonly used in residential and industrial applications, such as controlling ac and dc electrical devices, for signal and load switching, and for light dimming applications.