Q4004L4

Triacs Overview

The Littelfuse Q4004L4 is a Quadrac device, which integrates a triac and a diac trigger within a single package. It functions as a bidirectional AC switch controlled by gate polarity for main terminal voltage. The component features a TO-220 package with electrical isolation of 2500V rms from leads to the mounting surface. Key electrical parameters include an on-state RMS current of 4A, a rated repetitive off-state voltage (VDRM) of 400V, and a breakover voltage range of 33V to 43V. It operates within a temperature range of -40°C to +125°C.

Triacs Feature Summary

• Integrated diac trigger eliminates the need for discrete components and assembly time.
• Electrically isolated TO-220 package removes the requirement for external insulators.
• Glass-passivated junctions ensure long-term reliability and parameter stability.

Triacs Applications

• AC switching applications
• Phase control circuits
• Speed controls
• Temperature modulation controls
• Lighting controls requiring noise immunity

Triacs Procurement Notes

Verify the specific suffix 'L4' against official Littelfuse documentation to confirm exact pinout and mechanical dimensions. Confirm RoHS compliance status through the manufacturer's current datasheet. Check for obsolescence or lifecycle changes directly with Littelfuse, as distribution channels may not reflect real-time inventory or production status.

Triacs Selection Notes

Select this component when a combined triac-diac solution is required for AC phase control. Ensure the 400V voltage rating meets circuit requirements. Verify that the 2500V rms isolation capability satisfies safety standards without additional insulation materials. Confirm thermal management capabilities for the TO-220 package under expected load conditions.

Triacs Part Context

The Q4004L4 belongs to the Teccor QxxxxLTx series of Quadrac devices developed by Littelfuse. These devices are designed to simplify AC switching designs by integrating the trigger mechanism. The series offers various current and voltage ratings in TO-220 packages, providing a robust solution for industrial and consumer AC control applications.

Triacs Replacement Considerations

Direct substitutes must be verified as integrated Quadrac devices with similar 4A/400V ratings. Generic triacs require external diacs and snubber networks, altering the design. Consult Littelfuse for cross-reference lists to ensure functional equivalence in isolation and triggering characteristics.