Q4008LTH

Triacs Overview

The Q4008LTH is an internally triggered TRIAC from Littelfuse Inc., belonging to the Quadrac device family. It integrates a diac trigger within the same package as the triac, eliminating the need for discrete external triggering components. The device features an 8A RMS on-state current and a 400V blocking voltage rating. It is housed in a TO-220-3 Isolated Tab package, providing electrical isolation of 2500V rms between leads and the mounting surface. The component operates within a junction temperature range of -40°C to 125°C.

Triacs Feature Summary

• Integrates a diac trigger inside the package to simplify circuit design and reduce assembly time.
• Eliminates the need for external snubber networks due to alternistor technology.
• Provides high electrical isolation via an electrically isolated TO-220 package.

Triacs Applications

• AC switching and phase control applications
• Speed controls for motors
• Temperature modulation controls
• Lighting controls requiring noise immunity

Triacs Procurement Notes

Verify the manufacturer date code and lot traceability upon receipt. Confirm that the TO-220-3 Isolated Tab package matches the mechanical footprint requirements of the target PCB layout. Ensure storage conditions maintain component integrity prior to soldering.

Triacs Selection Notes

Select this part when a single-component solution for AC phase control is required without external gate drivers. The integrated diac simplifies bill of materials. Verify that the 400V voltage rating and 8A current capacity meet the specific load requirements of the application circuit.

Triacs Part Context

This component is part of the Teccor brand Quadrac series developed by Littelfuse. These devices are designed to replace separate triac and diac assemblies. The QxxxxLTx series offers various current and voltage ratings in the TO-220 package for robust industrial and consumer applications.

Triacs Replacement Considerations

Compatible substitutes include other parts from the QxxxxLTx series with matching voltage and current ratings. Verify pinout compatibility and thermal resistance characteristics before substituting with generic internally triggered TRIACs.

Triacs FAQ

Does the Q4008LTH require an external snubber network?

No, the Q4008LTH utilizes alternistor technology which eliminates the need for an external snubber network.

What is the electrical isolation rating of the package?

The TO-220 package provides electrical isolation of 2500V rms from the leads to the mounting surface.

How does the internal trigger mechanism benefit the design?

The integrated diac trigger saves the user the expense and assembly time associated with buying and assembling a discrete diac with a gated triac.