The optocouplers provide protection and high-speed switching
An optocoupler, also known as an opto-isolator, is an integral part of the opto electronics arena. It has fast proven its utility as an electrical isolator or a high-speed switch, and can be used in a variety of applications.
The basic design for optocouplers involves use of an LED that produces a light signal to be received by a photodiode to detect the signal. In this way, the output current or current allowed to pass can be varied by the intensity of light.
A very common application for the opto coupler is a FAX machine or MODEM, isolating the device from the telephone line to prevent the potentially destructive spike in voltage that would accompany a lightning strike. This protective tool has other uses in the opto electronic area. It can be used as a guard against EMI, removing ground loops and reducing noise.
This makes the optocoupler ideal for use in switching power supply and motor control applications. Today as semiconductors are being designed to handle more and more power, isolation protection has become more important than ever before.
Most notably the NEC Corporation is transferring knowledge developed from the opto semiconductors used in the communications industry to further improve the speed and reliability of the optocoupler.
