The HCPL4503 is a Dual channel high-speed Optocoupler with Transistor output. HCPL4503 consists of an AIGaAS LED optically coupled to a high-speed photodetector transistor. It can switch at a speed of 1 Mbit/s with Bandwidth 2MHz.
For easy integration with Digital system applications Vishay intertechnology has launched a new series of high speed Optocouplers called VOH1016A. These Optocouplers can operate upto 1MBd and also features an open collector transistor output with Schmitt-Trigger functionality.
6N139 is an optocoupler IC designed for isolating primary circuit and secondary circuit electrically but the pair of LED and photodiode - Darlington setup forms the triggering mechanism between the two sides.