QK040K4TP

Triacs Overview

The Littelfuse QK040K4TP is a four-quadrant TRIAC (Altistructor) rated for 800V repetitive peak off-state voltage and 40A RMS on-state current. It features a non-repetitive surge current capacity of 500A and a maximum on-state voltage of 1.6V. The device operates within a junction temperature range of -40°C to +150°C and utilizes an SMTO-218 through-hole package with an isolated tab. Key gate parameters include a maximum holding current of 80mA, a gate trigger voltage of 1.3V, and a gate trigger current of 100mA.

Triacs Feature Summary

• Four-quadrusensitive gate triggering capability for reliable operation across all quadrants.
• High thermal stability supporting continuous operation up to +150°C junction temperature.
• Isolated mounting tab design facilitates secure heat sink attachment in high-voltage applications.

Triacs Applications

• Industrial motor speed control systems
• Solid-state relay modules
• High-power AC switching circuits

Triacs Procurement Notes

Verify the specific suffix 'K4' against official Littelfuse documentation to confirm the exact 800V rating and gate sensitivity class. Ensure the procurement channel provides valid traceability data. Confirm that the SMTO-218 package dimensions match the target PCB footprint requirements before finalizing orders.

Triacs Selection Notes

Select this component when an 800V blocking voltage is required alongside 40A continuous current handling. The 1.6V on-state voltage offers lower conduction losses compared to higher voltage variants. Consider the 100mA gate trigger current for driver compatibility. The isolated tab is critical for safety in grounded heat sink configurations.

Triacs Part Context

This part belongs to the Qxx40xx series of Altistructors from Littelfuse. These devices are designed as robust alternatives to standard TRIACs, offering improved dv/dt immunity and ruggedness. The series targets industrial power control applications requiring high reliability and thermal performance in compact through-hole packages.

Triacs Replacement Considerations

Direct substitutes must match the 800V/40A rating and SMTO-218 isolated package. Verify gate trigger characteristics closely, as variations can affect circuit stability. Cross-reference with other Littelfuse Q-series parts or equivalent industry offerings ensuring identical pinout and thermal resistance specifications.