QK004V4

Triacs Overview

The Littelfuse QK004V4 is a standard TRIAC housed in a TO-251 (V-Pak/I-Pak) through-hole package. It features a 1 kV repetitive peak off-state voltage and a 4 A on-state current rating. The device supports an on-state gate trigger current of up to 25 mA and offers a non-repetitive surge current capacity of 46 A at 50 Hz or 55 A at 60 Hz. Designed as a bi-directional solid-state switch, it operates within a junction temperature range typical for thyristors and is RoHS compliant.

Triacs Feature Summary

• Bi-directional solid-state switching capability for AC control applications
• High voltage blocking performance with 1 kV off-state rating
• Robust surge handling suitable for inductive loads

Triacs Applications

• Motor speed control systems
• Temperature modulation circuits
• General AC phase control applications

Triacs Procurement Notes

Verify component authenticity against Littelfuse official documentation due to market availability variations. Confirm that the specific suffix V4 corresponds to the required packaging and compliance standards. Check current distribution status as some sources indicate discontinuation or limited stock. Ensure replacement parts meet identical electrical specifications if original supply is unavailable.

Triacs Selection Notes

Select this component for low-power AC switching tasks requiring moderate current handling. Evaluate thermal management requirements based on the TO-251 package limitations. Consider the 25 mA gate trigger threshold for driver compatibility. Assess surge current ratings against potential load inrush conditions during startup phases.

Triacs Part Context

This part belongs to the QK series of low-power TRIACs from Littelfuse. The series is engineered for general-purpose AC power control where compact size and reliable switching are prioritized. The TO-251 package provides a balance between thermal dissipation and board space efficiency for consumer and industrial electronics.

Triacs Replacement Considerations

DigiKey lists parametric equivalents as available substitutes. Verify that any replacement matches the 1 kV voltage, 4 A current, and TO-251 package dimensions. Cross-reference datasheets to ensure identical gate trigger characteristics and surge ratings before implementation.