ACST6-8ST

Overview

The ACST6-8ST is a six-ampere snubberless triac from STMicroelectronics, designed for general-purpose AC switching applications. It supports on/off and phase angle control functions in circuits requiring high commutation capability. The device operates without an external snubber circuit when datasheet limits are respected. It features a through-hole package suitable for robust mounting. Key electrical parameters include an RMS current of 6 A, a repetitive peak off-state voltage of 800 V, and a maximum junction temperature of 125°C. It is optimized for resistive loads and offers three-quadrant triggering sensitivity.

Feature Summary

• Snubberless design eliminates the need for external RC networks under specified conditions
• Logic-level gate drive allows direct interfacing with microcontrollers
• High static and dynamic commutation capabilities for reliable switching
• Three-quadrant triggering for flexible gate control configurations

Applications

• General purpose AC load switching
• Phase angle control for lighting dimmers
• Motor speed control for small appliances
• Solid state relay implementations

Procurement Notes

Verify the specific suffix '8ST' against official STMicroelectronics documentation to confirm pinout and thermal characteristics. Ensure the ordering code matches the exact package variant required for your PCB layout. Cross-reference with the latest datasheet revision to confirm compliance with RoHS and halogen-free standards before finalizing procurement.

Selection Notes

Select this component for applications requiring 6A RMS current handling at 800V blocking voltage. It is suitable where snubberless operation simplifies the bill of materials. Consider the through-hole package for mechanical stability. Verify that the load current does not exceed the rated RMS value and that the dv/dt ratings are sufficient for the specific application environment.

Part Context

This part belongs to the ACST series of AC switches, which integrates overvoltage protection and gate level shifting. Unlike standard triacs, these devices offer enhanced protection against line transients. The ACST6-8ST specifically provides a cost-effective solution for medium-power AC control tasks in residential and industrial equipment.

Replacement Considerations

Direct replacements may include other 6A 800V snubberless triacs from the same manufacturer family. Verify equivalent current ratings, voltage thresholds, and package dimensions. Ensure the replacement maintains the same triggering sensitivity and thermal performance characteristics.