ACS108-8SA-TR

Overview

The ACS108-8SA-TR is an overvoltage protected AC switch from STMicroelectronics, utilizing A.S.D.® technology to control loads up to 0.8 A RMS. It features a built-in overvoltage crowbar structure for absorbing inductive turn-off energy and a gate level shifter driver for digital controller isolation. Triggered by negative gate current, it operates within a junction temperature range of -30°C to +125°C. Key electrical parameters include a maximum on-state RMS current of 0.45 A at Tamb = 64 °C, a blocking voltage (VDRM/VRRM) of 800 V, and a maximum gate trigger current (IGT) of 10 mA. The device is housed in a TO-92 package.

Feature Summary

• Enables equipment compliance with IEC 61000-4-5 surge standards through integrated overvoltage crowbar technology.
• Provides high noise immunity against static dV/dt and IEC 61000-4-4 burst events without requiring external snubbers or varistors.
• Interfaces directly with microcontrollers via a gate level shifter driver that separates the digital controller from the main switch.
• Supports common package tab connections to facilitate the mounting of multiple AC switches on a single cooling pad.

Applications

• Alternating current on/off static switching in appliances and industrial control systems
• Driving low power high inductive loads such as relays, valves, solenoids, and dispensers
• Controlling resistive loads including lamps, fans, pumps, and door locks

Procurement Notes

Verify the specific ordering suffix to confirm packaging configuration, as TR denotes tape and reel packing. Confirm component status and environmental compliance details, such as RoHS and REACH status, prior to finalizing procurement orders. Ensure design specifications align with the absolute maximum ratings provided in the official datasheet.

Selection Notes

Select this component for applications requiring direct microcontroller interfacing and robust protection against mains transients. The integrated crowbar mechanism eliminates the need for external protective components like varistors, reducing overall bill of materials. Ensure the load current remains within the specified RMS limits and consider thermal management requirements for the TO-92 package during selection.

Part Context

The ACS108-8SA-TR belongs to the ACS™ family of overvoltage protected AC switches manufactured by STMicroelectronics. This series utilizes proprietary A.S.D.® technology to provide enhanced ruggedness against electrical stress. The part is designed for compact designs where space savings and simplified circuit topologies are prioritized over traditional triac solutions requiring external protection networks.

Replacement Considerations

Direct replacements must match the 800 V blocking voltage, 0.8 A current rating, and TO-92 package. Verify compatibility with negative gate triggering logic. Other variants within the ACS108 series may offer different current ratings or packaging options but share similar functional characteristics.