Q4015LT

Triacs Overview

The Littelfuse Q4015LT is a Quadrac device, which integrates a triac and a diac trigger within a single package. It functions as a bidirectional AC switch with gate control for either polarity of main terminal voltage. The component features a 400V repetitive peak off-state voltage (VDRM) and an RMS on-state current (ITRMS) capacity of 15A. It utilizes a TO-220 package with electrical isolation of 2500V rms from the leads to the mounting surface. Key electrical parameters include a holding current of 33mA, latching current of 43mA, and a maximum on-state voltage of 1.6V at rated current.

Triacs Feature Summary

• Integrated Diac Trigger: Combines a triac and diac in one package to eliminate external components and assembly time.
• High Voltage Isolation: Provides 2500V rms isolation between leads and mounting surface, removing the need for separate insulators.
• Glass-Passivated Junctions: Ensures long-term device reliability and parameter stability through glass-passivated chip junctions.

Triacs Applications

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

Triacs Procurement Notes

Verify the specific suffix against the official datasheet to confirm exact ratings and packaging options. Ensure the selected variant matches the required voltage and current specifications for the target application. Confirm RoHS compliance status if environmental regulations apply to the end product design.

Triacs Selection Notes

Select this component for applications requiring integrated phase control without discrete diacs. Consider the 2500V isolation capability when designing circuits where mounting surface contact is possible. Verify that the 15A current rating and 400V blocking voltage exceed the circuit's maximum operating conditions.

Triacs Part Context

This part belongs to the Teccor QxxxxLTx series of Quadrac devices manufactured by Littelfuse. These devices are designed to simplify AC switching designs by integrating the trigger mechanism. The series offers various current and voltage ratings within the TO-220 package format.

Triacs Replacement Considerations

Direct substitutes must be verified against the official Littelfuse cross-reference list. Generic triacs require additional discrete diac components and snubber networks, altering the PCB layout and bill of materials.

Triacs FAQ

What is the primary advantage of using a Quadrac over a standard Triac?

The Quadrac integrates a diac trigger inside the same package, saving the user the expense and assembly time of buying and assembling a discrete diac with a gated triac.

Does the Q4015LT require an external snubber network?

Standard Quadrac devices typically require snubber networks for protection. However, the alternistor variant (QxxxxLTH) is specifically designed to eliminate the need for a snubber network.

What is the isolation rating of the TO-220 package for this device?

The TO-220 package provides electrical isolation of 2500V rms from the leads to the mounting surface, eliminating the need for separate insulators.