ACST12-7ST

Overview

The ACST12-7ST is a transient protected AC power switch from STMicroelectronics, utilizing ASD technology. It integrates a TRIAC structure with an overvoltage crowbar device to absorb inductive turn-off energy and withstand line transients per IEC 61000-4-5. Designed for home appliances and industrial systems, it drives loads up to 12 A. The 'S' suffix indicates low gate current sensitivity (IGT max 10 mA) and high electrical noise immunity compliant with IEC 61000-4-4. It operates in a TO-220AB package with a maximum repetitive peak off-state voltage of 700 V.

Feature Summary

• Integrates Triac with overvoltage crowbar technology
• Low gate triggering current requirement
• High static dV/dt immunity
• Compliance with IEC 61000-4-5 and IEC 61000-4-4 standards

Applications

• AC mains static switching in appliance control systems
• Universal drum motor drive in washing machines
• Compressor drive for refrigerators or air conditioners

Procurement Notes

Verify the specific ordering code against the manufacturer's official documentation to ensure correct package and sensitivity selection. Confirm that the component meets RoHS compliance requirements for your target market. Check for any environmental declarations such as ECOPACK specifications. Ensure the procurement channel provides valid traceability for the electronic component.

Selection Notes

Select the ACST12-7ST when low gate drive current is required, specifically where MCU direct driving is intended without additional amplification. This variant offers a maximum gate trigger current of 10 mA compared to the 35 mA option. Verify that the application requires the specific noise immunity characteristics associated with the 'S' designation rather than the higher dV/dt immunity of the 'C' version.

Part Context

This component belongs to the ACS/ACST family built with Application Specific Discrete (ASD) technology. The series is engineered for medium power AC load control in domestic and industrial environments. It combines standard TRIAC functionality with integrated protection features to reduce external passive component counts and simplify circuit design for AC power switching applications.

Replacement Considerations

The ACST12-7CG serves as a surface-mount alternative within the same series, offering identical electrical characteristics in a D²PAK package. Designers requiring a different sensitivity level should consider the ACST12-7CT, which utilizes a 35 mA gate trigger current specification while maintaining the same voltage and current ratings.