Q4008R4

Triacs Overview

The Littelfuse Q4008R4 is a bidirectional triac designed for AC power control applications. It features an RMS on-state current rating of 8 A and a repetitive peak off-state voltage (VDRM) of 400 V. The device operates within a temperature range of -40 °C to +125 °C and utilizes a TO-220AB package with through-hole mounting. Key electrical characteristics include a maximum holding current of 50 mA, a gate trigger voltage of 2.5 V, and a gate trigger current of 25 mA. The on-state voltage is specified at 1.6 V, while the non-repetitive peak on-state current reaches 83 A or 100 A depending on pulse duration.

Triacs Feature Summary

• Bidirectional switching capability for alternating current circuits
• Robust thermal performance suitable for high-temperature environments up to 125 °C
• High surge current handling capacity for inductive load protection

Triacs Applications

• Solid-state relays
• Motor speed control systems
• Lighting dimmer circuits

Triacs Procurement Notes

Verify the specific suffix 'R4' against the manufacturer's official datasheet to confirm pinout configuration and packaging details. Ensure compatibility with existing PCB footprints for the TO-220AB package. Cross-reference regulatory compliance status such as UL certification before final integration into safety-critical designs.

Triacs Selection Notes

Select this component when a 400 V blocking voltage and 8 A continuous current are required for AC loads. Consider the 25 mA gate drive requirement for driver circuit design. Evaluate thermal management needs based on the 1.6 V on-state voltage drop and expected ambient temperatures within the -40 °C to +125 °C operating range.

Triacs Part Context

This part belongs to the Qxx08xx series of triacs from Littelfuse, which are engineered for general-purpose AC power switching. The series offers standardized electrical parameters to simplify design across various industrial and consumer power control modules requiring reliable thyristor-based switching solutions.

Triacs Replacement Considerations

Check for direct equivalents within the same voltage and current class. Verify that any substitute maintains identical gate trigger specifications and package dimensions to ensure mechanical and electrical interchangeability without redesign.