Optocouplers fit into tight spaces

By Gina Roos, editor-in-chief

Vishay Intertechnology, Inc. has launched two new series of optocouplers with phototriac output in space-saving DIP-4 and SMD-4 packages. Vishay Semiconductors’ VOT8024A and VOT8121A series feature a high off-state voltage of 800 V and dV/dt of 1,000 V/μs, together with high robustness and noise isolation for home appliances and industrial equipment.

The devices consist of a GaAs infrared LED optically coupled to either a zero-crossing TRIAC (VOT8024A series) for EMI reduction without the need for external snubber networks or a random-phase TRIAC (VOT8121A series) to enable phase-independent switching, saving cost and board space. They isolate low-voltage logic from 120-VAC, 240-VAC, and 380-VAC lines to control resistive, inductive, or capacitive loads, including motors, solenoids, high-current thyristors, or TRIACs and relays.

The high off-state voltages of both the VOT8024A and VOT8121A series improve safety margins in one-phase applications while maintaining enough voltage headroom for three-phase applications, said Vishay, and for additional safety, the optocouplers offer a withstanding isolation voltage of 5,000 VRMS. For easy interfacing with digital logic, the VOT8024A series offers low trigger currents of 5 mA, while the VOT8121A provides low trigger currents of 10 mA.

Applications include power TRIAC drivers in solid-state relays, three-phase air conditioners, boilers, thermostats, industrial motor control, and power line switching, as well as motor, lamp, and valve control in household appliances.

Samples and production quantities are available with lead times of six weeks. Pricing for U.S. delivery is $1.50 per piece. Devices are RoHS-compliant.