Triac STMicroelectronics EB168891121 600V 4A semiconductor switch (Triac)

Triac STMicroelectronics EB168891121 600V 4A semiconductor switch (Triac) is a bidirectional AC switch designed for integration in control and power electronic circuits. Rated for 600 volts and a nominal current of 4 amperes, this compact triac enables control of alternating-current loads by conducting in both directions when triggered. It is suitable for switching and phase-control applications where reliable conduction and compact footprint are required.

Advantages

The triac provides bidirectional conduction for AC circuits, enabling control of both halves of the waveform without requiring a bridge or additional polarity switching. Its 600 V voltage rating and 4 A current capacity make it suitable for a range of low- to medium-power mains applications. The compact package supports dense PCB layouts and integration into motor controllers, light dimmers, and solid-state relay designs.

Suitable for

• Phase-angle control of AC motors and fan speed regulation
• Light dimming and heater power regulation
• Solid-state relay and AC switching modules
• Small household appliance control and industrial control circuits

Key specifications

• Maximum repetitive off-state voltage: 600 V
• Nominal on-state current: 4 A
• Bidirectional AC conduction (Triac operation)
• Compact semiconductor package suitable for PCB mounting
• Designed for phase-control switching and general AC load switching

How to use

Integrate the triac into the AC switching circuit following the manufacturer’s recommended layout and gate drive practice. Provide an appropriate gate-trigger network to ensure reliable firing at the intended phase angle; typical gate components include resistors, diodes, and optoisolators for isolation in control circuits. Observe proper heat dissipation measures and use a heatsink or thermal vias on the PCB if continuous currents approach the device rating.

Usage recommendations

Verify the expected load current, transient conditions and ambient temperature to ensure operation within the triac’s ratings. Use snubber networks or RC filters to limit dV/dt and prevent unintended triggering in inductive or noisy environments. For safety and EMC performance, follow isolation and grounding best practices and consult detailed datasheet parameters when designing the final circuit.