MOC3163SM

Optoisolators - Triac, SCR Output

The MOC3163SM Optocoupler (also known as an optoisolator) by Vishay Semiconductor is a basic opto-triac integrated circuit output optocoupler. This device consists of an infra-red emitting diode optically coupled to a triac. It is typically used in circuitry requiring isolation between a low-level logic control and power controls.

Application Field

The MOC3163SM Optocoupler can find application in any area that requires interfacing of logic level and non-logic level circuitry. It is used in motor control, power switching, lamp control, AC power line control, switched mode power supplies, thyristor control, smart switches, industrial automation circuitry and more. It is often the active element in optically-triggered triac circuits.

Working Principle

The optocoupler consists of an infrared (IR) emitting diode and an optically coupled triac. The diode works in conjunction with the triac to provide a high degree of electrical isolation between the input signal and output power switching. The optocoupler can be triggered by digital signals from micro-controllers, relays or other control systems. When a small current passes through the diode, it emits light and activates the photo-coupled triac. When the triac is activated, it conducts and switches the output waveform at a specific voltage.

The basic circuit of a MOC3163SM optocoupler consists of a LED emitting diode, a bidirectional triac or silicon controlled rectifier, and a proprietary photo-sensitive gate circuit. When the LED is activated by a small voltage, it produces light which in turn is detected by the opto-subcircuit. The opto-subcircuit generates a voltage drop across the triac/SCR and triggers it into conduction, allowing current to flow in the output circuit.

Conclusion

The Vishay MOC3163SM is an easy-to-use optocoupler ideal for any circuitry requiring interface between a logic control and power transistors. It is an opto-triac design, consisting of a LED and a triac or SCR. When the LED is activated by a small voltage, it produces light and triggers the triac/SCR into conduction, which allows current to flow in the output circuit. This device is frequently used in motor control, power switching, lamp control, AC power line control, smart switches, and more.