ACST12-7SG-TR

Overview

The ACST12-7SG-TR is a transient protected AC power switch manufactured by STMicroelectronics, utilizing ASD technology. It integrates a Triac structure with an overvoltage clamping device to absorb inductive turn-off energy and withstand line transients per IEC 61000-4-5 standards. The device features a sensitive gate requiring low triggering current (IGT max 10 mA) while providing high noise immunity (static dV/dt min 200 V/µs). Rated for 12 A RMS on-state current and 700 V repetitive peak off-state voltage, it operates within a junction temperature range of -40 °C to +125 °C. It is supplied in a D²PAK package.

Feature Summary

• Integrates Triac structure with overvoltage crowbar technology for self-protection against line transients
• Sensitive gate design enables direct drive from microcontrollers with low triggering current requirements
• High electrical noise immunity compliant with fast transient standards without external snubbers

Applications

• AC mains static switching in appliance control systems
• Drive of universal drum motors in washing machines
• Compressor control for refrigerators or air conditioners

Procurement Notes

Verify the specific ordering code ACST12-7SG-TR to confirm the D²PAK package and tape-and-reel packing mode. Ensure the application requires the 10 mA sensitive gate variant rather than the 35 mA version. Confirm thermal management capabilities align with the specified junction-to-ambient resistance values for the target PCB copper area.

Selection Notes

Select this component for medium-power AC load applications requiring robust transient protection. The D²PAK package offers lower thermal resistance compared to TO-220AB when mounted with adequate copper surface area. Verify that the system's MCU can supply the required gate current and that the load characteristics fall within the 12 A RMS and 126 A surge limits.

Part Context

This part belongs to the ACST12 series, which provides a rugged alternative to conventional TRIACs for home appliances and industrial systems. The series utilizes Application Specific Discrete (ASD) technology to embed high-voltage clamping devices directly into the silicon die, eliminating the need for external overvoltage protection components.

Replacement Considerations

Direct replacements include other ACST12 variants such as ACST12-7CT or ACST12-7CG depending on the required package type and gate sensitivity specifications.