What is an Optocoupler and How does it Works?

Electrical
2

What aspects should you know to select an optocoupler?

There are various types of optocouplers, with the decision depending on the intended use. In any event, all optocouplers have the maximum parameters listed below:

  1. The forward current (IF) of the emitting diode & the reverse voltage (VR) should not be exceeded.
  2. The optocoupler has a phototransistor output, collector current (IC), & collector-emitter voltage (VCE).

Additionally, the functioning of these properties at various operating temperatures needs to be considered. Typically, the manufacturer’s datasheets provide de-rating curves that illustrate the impacts.

Finally, probably the most essential characteristic in an optocoupler is CTR (Current Transfer Ratio), which is the percentage ratio of an optocoupler’s output current (IC) to its input current (IF).

CTR% = [(IC(in mA)/IF(in mA))] X 100