MOC3021 Circuit & Diagram | Triac Driver Isocom Components 2004 LTD

moc3021 optocoupler| moc3021 triac driver circuit|

MOC3021

The MOC3021 is an optically isolated TRIAC driver IC, featuring an internal infrared LED and a phototriac to safely isolate low-voltage control circuits from high-voltage AC loads. It’s widely used in AC lamp dimming, motor control, and heating element switching applications, offering quick response times and the advantage of no mechanical contact wear.

MOC3021 Pinout

MOC3021 Equivalent

The table above lists several equivalent models to the MOC3021 optotriac, highlighting their key parameters like isolation voltage, LED forward current, TRIAC voltage, and package type. All these models offer robust optical isolation (7500V) and consistent LED current ratings (15mA). However, the MOC3063 stands out with a higher TRIAC voltage capability of 600V, making it suitable for applications with higher voltage requirements. When selecting a replacement, ensure the chosen model meets your circuit’s specific voltage and isolation criteria.

MOC3021 TRIAC Driver Circuit Example

This circuit uses the MOC3021 optocoupler to electrically isolate a low-voltage control circuit from a high-voltage AC load. When the control side (such as a microcontroller) outputs a high-level signal, the internal infrared LED inside the MOC3021 turns on, activating the internal phototriac. This, in turn, triggers the external  TRIAC, allowing current to flow to the AC load.