ACST2-8SB

Overview

The ACST2-8SB is a surface-mount overvoltage protected AC switch from STMicroelectronics, belonging to the ACS/ACST power switch family. It features a Triac structure with integrated high voltage clamping technology to absorb inductive turn-off energy and withstand line transients per IEC 61000-4-5 standards. The device operates with an on-state RMS current of 2 A and a repetitive peak off-state voltage of 800 V. It requires a low gate trigger current (IGT max 10 mA) for activation while maintaining high electrical noise immunity with a static dV/dt greater than 500 V/µs at 125 °C. Packaged in DPAK, it interfaces directly with microcontrollers.

Feature Summary

• Integrates Triac structure with overvoltage crowbar technology for self-protection against line transients
• Provides high electrical noise immunity compliant with IEC 61000-4-4 fast transient burst test standards
• Enables direct interface with logic level circuits due to low gate trigger current requirement

Applications

• AC on/off static switching in home appliances and industrial control systems
• Driving low power highly inductive loads such as solenoids, pumps, fans, and micro-motors

Procurement Notes

Verify the specific package suffix 'B' corresponds to the DPAK surface-mount configuration when sourcing components. Confirm that the ordering code matches the required delivery mode, as tube or tape-and-reel options may be available for this series. Ensure compliance with environmental directives such as RoHS and ECOPACK specifications relevant to the manufacturing batch.

Selection Notes

Select this component for applications requiring robust protection against inductive kickback and line surges without external snubber circuits. The low gate sensitivity allows for direct driving by standard microcontroller outputs. Consider thermal derating curves when designing for continuous operation near the maximum 2 A rating or elevated ambient temperatures.

Part Context

This device is part of the ACST2 series within the broader ACS/ACST power switch family. It shares core technologies like ASD (Application Specific Discrete) design with other variants in the lineup, differing primarily in current ratings and packaging options such as TO-220FPAB or DPAK.

Replacement Considerations

Direct substitutes include other ACST2 series variants like ACST210-8B if pin compatibility and package dimensions are identical. Cross-family replacements require verification of voltage ratings, current handling capabilities, and gate trigger characteristics to ensure functional equivalence.