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Vishay’s VOT8024AM and VOT8121AM are new optocouplers which have a phototriac output for use as robust, isolated AC switches in home appliances and industrial equipment.

The devices feature a high off-state voltage rating of 800V and handle dV/dt swings of 1,000V/μs, offering equipment designers a robust switch solution which provides high noise isolation.

These optocouplers isolate low-voltage logic circuits from 120V, 240V, and 380V AC lines to provide a means to control resistive, inductive or capacitive loads, including motors, solenoids, high-current thyristors, or triacs and relays. They consist of a GaAs infrared LED optically coupled to either:

  • A zero-crossing triac in the case of the VOT8024AM for EMI reduction without the need for external snubber networks
  • A random-phase triac in the case of the VOT8121AM to enable phase-independent switching.

The high off-state voltage of the VOT8024AM and VOT8121AM enhances safety margins in one-phase applications, while still maintaining enough voltage headroom for three-phase applications. For additional safety, the optocouplers offer a withstanding isolation voltage of 3,750Vrms. Low trigger currents of 5mA for the VOT8024AM and 10mA for the VOT8121AM facilitate an easy interface with the digital logic outputs of microcontroller-based IoT AC control systems. The 1,000V/μs load-slew immunity reduces the need for large, costly and inefficient snubber circuits.

Vishay’s VOT8024AM and VOT8121AM optocouplers are housed in a compact flat SOP-4 package.

  • 100mA on-state current
  • 1.2V forward voltage
  • 400μA holding current
  • Zero-voltage crossing detector
  • >5mm creepage and clearance distances
  • Power triac driver in solid-state relays
  • 3-phase AC equipment
  • Motor control
  • Industrial control
  • White goods and household electrical equipment
  • Lighting controls


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