ACST10-7ST

Overview

The ACST10-7ST is a bidirectional triac power switch from STMicroelectronics, designed for AC mains static switching in home appliances and industrial control systems. It integrates an overvoltage crowbar protection mechanism to absorb inductive turn-off energy and withstand transients per IEC 61000-4-5 standards. The device supports an on-state RMS current of 10 A with a rated repetitive peak off-state voltage of 700 V. It features low gate triggering current (IGT < 10 mA) for direct MCU interfacing and high static dV/dt immunity exceeding 2000 V/µs. Packaged in a TO-220AB insulated housing, it provides robust thermal performance and insulation up to 1500 Vrms.

Feature Summary

• Integrates Triac structure with overvoltage crowbar technology for self-protection against line surges
• Offers high noise immunity with static dV/dt greater than 2000 V/µs
• Requires low gate trigger current for activation while maintaining high reliability
• Provides UL certified insulation rated at 1500 Vrms within the package

Applications

• AC mains static switching in appliance and industrial control systems
• Driving universal motors such as washing machine drums
• Compressor control for refrigerators or air conditioners

Procurement Notes

Verify the specific ordering code matches the required package variant, as the datasheet lists ACST1010-7T for TO-220AB and ACST1010-7FP for TO-220FPAB. Confirm that the 'S' suffix in the query corresponds to the standard TO-220AB configuration rather than the insulated FP version. Ensure compliance with environmental specifications such as ECOPACK grades if lead-free requirements are necessary for the target assembly process.

Selection Notes

Select this component when driving medium-power AC loads up to 10 A without requiring external snubber circuits for turn-off commutation. The low gate trigger current allows direct connection to microcontrollers via a simple resistor. Choose the insulated TO-220FPAB package if electrical isolation between the heatsink and the circuit ground is mandatory, otherwise use the standard TO-220AB for cost-sensitive designs.

Part Context

The ACST10 series belongs to the ACS/ACST power switch family built with Application Specific Discrete (A.S.D.) technology. This family is optimized for home appliances and industrial systems, combining high-performance triac switching with integrated transient voltage suppression capabilities to simplify system design and reduce passive component counts.

Replacement Considerations

Standard triacs lacking integrated overvoltage protection cannot directly replace this part without adding external clamping circuits. Verify that any substitute device meets the 10 A RMS current rating and 700 V blocking voltage. Check if the replacement offers comparable dV/dt immunity to avoid false triggering in noisy environments.