Q401E3

Triacs Overview

The Littelfuse Q401E3 is a bidirectional triac in the Teccor QxxxxLTx series, rated for 4 A RMS on-state current and 400 V repetitive peak off-state voltage. It utilizes a TO-220 package with an electrically isolated tab rated at 2500 V rms from the leads to the mounting surface. The device features glass-passivated junctions for parameter stability and includes an integrated diac trigger mechanism within the same package. Key electrical characteristics include a maximum gate trigger current of 10 mA, a maximum gate trigger voltage of 1.3 V, and a surge current rating of 55 A. It operates within a temperature range of -40°C to 125°C.

Triacs Feature Summary

• Integrated Diac Trigger: Combines a triac and diac in one package to simplify circuit design and reduce assembly time.
• Electrically Isolated Tab: Provides 2500 V rms isolation between the mounting surface and leads, eliminating the need for external insulators.
• Glass-Passivated Junctions: Ensures long-term device reliability and stable parameters under harsh conditions.

Triacs Applications

• AC speed controls
• Temperature modulation controls
• Lighting controls requiring noise immunity

Triacs Procurement Notes

Verify the specific suffix 'E3' against official Littelfuse documentation to confirm compliance status or material composition changes. Ensure the selected component matches the required voltage and current ratings for the target application. Cross-reference the part number with authorized distributors to confirm availability and authenticity before procurement.

Triacs Selection Notes

Select this component for applications requiring AC phase control where noise immunity is critical. The integrated diac simplifies the drive circuit by removing the need for a discrete triggering component. Consider the thermal management requirements associated with the TO-220 package and the 4 A current rating when designing the heat dissipation strategy.

Triacs Part Context

This component belongs to the Teccor QxxxxLTx series of Quadrac devices manufactured by Littelfuse. These devices are designed as bidirectional AC switches that integrate a diac trigger inside the triac package. The series offers various current capacities ranging from 4 A to 15 A and voltage ranges from 200 V to 600 V, providing flexibility for different power control needs.

Triacs Replacement Considerations

Consult Littelfuse technical support for confirmed substitute part numbers. Verify compatibility regarding pinout, voltage ratings, and thermal characteristics before replacing the original component with any alternative device.

Triacs FAQ

What is the purpose of the integrated diac in the Q401E3?

The integrated diac eliminates the need for a discrete diac component, saving assembly time and reducing the overall cost of the circuit while ensuring reliable triggering.

How does the Q401E3 provide electrical isolation?

The TO-220 package features an electrically isolated tab that provides 2500 V rms isolation from the leads to the mounting surface, removing the requirement for separate insulators.

What type of junction protection does the Q401E3 use?

The device utilizes glass-passivated junctions to ensure long-term reliability and parameter stability across its operating temperature range.