MOC3043 IC Zero Cross Optoisolator Triac Driver IC

MOC3043 IC Zero Cross Optoisolator Triac Driver IC 

The MOC3043 is a zero-cross optoisolator triac driver IC designed for safe and reliable interfacing between low-voltage control electronics and high-voltage AC loads. It contains an infrared LED input and a light-activated phototriac output with built-in zero-cross detection circuitry, providing high electrical isolation and clean switching of AC loads.

The MOC3043 triggers an external triac only when the AC line voltage passes through the zero-voltage point, significantly reducing electrical noise, inrush current, and electromagnetic interference (EMI). This makes it ideal for ON/OFF switching applications where smooth and noise-free operation is required.

The main difference between the MOC304x family is the input LED trigger current—and the MOC3043 has the lowest trigger current, making it ideal for direct microcontroller drive.

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Features

• Zero-cross switching for low EMI
• Low LED trigger current (lowest in the MOC3040 series)
• High isolation voltage
• Output phototriac for triggering external triac gates
• Compatible with microcontroller outputs
• 6-pin DIP package
• High noise immunity and stable operation

Applications

• AC mains ON/OFF control
• Solid State Relays (SSR)
• Home appliances (lights, fans, motors, heaters)
• Industrial AC switching
• Automatic power controllers
• Safety-isolated control circuits
• HVAC systems
• EMI-sensitive switching systems

*Product image for illustration purposes only, actual product may vary.