ACST310-8B

Overview

The ACST310-8B is a bidirectional thyristor (AC switch) from STMicroelectronics, rated for 4 A RMS average on-state current and 800 V repetitive peak reverse voltage. It utilizes ASD technology to integrate a high-voltage clamping device that absorbs inductive turn-off energy and withstands line transients per IEC 61000-4-5. The component features a maximum gate trigger current of 10 mA and a maximum gate trigger voltage of 1 V, enabling direct microcontroller drive. It operates within a temperature range of -40°C to +125°C, with a surge current rating of 21 A and a holding current of 20 mA. Packaged in TO-252 (DPAK), it measures 6.73 mm in length, 6.22 mm in width, and 2.4 mm in height.

Feature Summary

• Integrates self overvoltage protection via an embedded high-voltage clamping device to absorb inductive turn-off energy.
• Enables direct microcontroller driving through low gate current requirements, simplifying circuit design.
• Provides high electrical noise immunity compliant with IEC standards such as fast transient burst tests.

Applications

• Home appliances including microwave ovens, cookers, washing machines, and water heaters
• Industrial systems requiring logic-level AC switching for resistive or inductive loads
• Residential appliance control circuits managing AC universal motors, lamps, and valves

Procurement Notes

Verify the specific ordering suffix and package variant during procurement, as the ACST310-8B is available in DPAK and other configurations. Confirm compliance with ECOPACK®2 standards and UL94-V0 flammability ratings if required by the application. Ensure the selected part matches the intended thermal and electrical specifications for the target system environment.

Selection Notes

Select the ACST310-8B when designing circuits that require integrated overvoltage protection to eliminate external MOVs or RC snubber networks. Its low gate trigger current allows direct interfacing with standard microcontrollers without additional driver stages. Consider the 800 V blocking capability and 3 A load capacity for general-purpose AC switching in residential and industrial equipment where space savings and reliability are critical.

Part Context

The ACST310-8B belongs to the ACS™ / ACST power switch family built with Application Specific Discrete (ASD®) technology. This series is designed to replace traditional triacs with snubber circuits by embedding protection mechanisms directly into the silicon die. The component supports three-quadrant operation (Q1, Q2, and Q3) and is optimized for applications demanding robust performance against line transients and electrical noise.

Replacement Considerations

Public confirmed substitute part numbers are not provided in the source material. Designers should consult official STMicroelectronics documentation for equivalent devices within the ACS/ACST family or comparable logic-level AC switches with similar voltage and current ratings.