STMicroelectronics ACS108-6SUF-TR

Overview

ACS108-6SUF-TR from STMicroelectronics is an overvoltage-protected AC line switch (ACS™) designed for direct microcontroller-driven AC load control in appliances and industrial systems. It delivers 0.8 A RMS on-state current, 600 V blocking voltage, and integrated crowbar-based overvoltage clamping (V_CL ≥ 650 V), enabling robust switching of inductive loads like solenoids, valves, and low-power motors without external snubbers or varistors.

For engineers reviewing the ACS108-6SUF-TR datasheet, ACS108-6SUF-TR pinout, ACS108-6SUF-TR application, or ACS108-6SUF-TR equivalent, key selection criteria include static dV/dt immunity (>500 V/µs), gate trigger current (10 mA), thermal resistance (R_th(j-t) = 14 °C/W), and SMBflat-3L package compatibility with shared cooling pads.

Technical Context

The ACS108-6SUF-TR integrates A.S.D.® technology to combine a high-voltage thyristor structure with an on-chip gate-level shifter and crowbar protection circuit. Its negative-gate-triggering logic (IGT = 10 mA, VGT ≤ 1 V) isolates digital controllers from mains-referenced switching paths while maintaining precise turn-on timing across quadrants II and III.

Clamping operation activates autonomously during inductive turn-off or IEC 61000-4-5 surges (up to 2 kV peak), limiting V_OUT to ≤650 V and dissipating stored energy in the dedicated avalanche section. Critical dI/dt capability (≥0.3 A/ms) and high noise immunity ensure reliable commutation without snubber networks.

Key Specifications

Pinout & Package

SMBflat-3L is a 3-terminal surface-mount package with an exposed metal tab serving as the COM terminal and primary thermal path. Dimensions: 3.3–3.95 mm × 5.1–5.6 mm × 0.9–1.1 mm (L × W × H); tab area supports direct PCB copper pour for thermal management.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar AC line switching applications.

Compared with ACS108-6SUF-TR, the bulk-packaged ACS108-6SUF offers identical performance at lower unit cost for low-volume builds, while the TO-92 ACS108-6S sacrifices thermal efficiency and surface-mount compatibility-making the -TR variant optimal for automated, thermally demanding, high-reliability AC control.

Availability

ACS108-6SUF-TR is available at Aetrix Electronics and suitable for home appliance control, industrial solenoid actuation, and smart HVAC fan control requiring stable component supply, RoHS-compliant packaging, and long-lifecycle availability.

Supply support for ACS108-6SUF-TR includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing analog, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The ACS™ family was developed specifically for robust, snubberless AC switching in cost-sensitive, space-constrained appliances and industrial controls-leveraging A.S.D.® integration to replace discrete triac-MOV-snubber combinations.

FAQ

What is the recommended gate resistor value for driving ACS108-6SUF-TR from a 3.3 V MCU GPIO?

A 330 Ω series resistor is recommended to deliver ~10 mA peak gate current (IGT) while limiting average gate power to <0.1 W. This ensures reliable triggering across temperature and accounts for VGT variation (≤1 V). The resistor must be rated for ≥0.25 W and placed close to the G pin to minimize noise coupling.

Can ACS108-6SUF-TR drive a 120 VAC, 0.5 A resistive heater load continuously?

Yes-it supports 0.8 A RMS at T_tab = 113 °C. With proper PCB copper area (≥5 cm²) under the tab, thermal resistance remains ≤14 °C/W, keeping junction temperature below 125 °C. Derating is not required for this load, but ambient temperature must stay ≤75 °C for full rating.

Does ACS108-6SUF-TR require zero-crossing detection for safe operation?

No-it operates independently of AC phase and supports arbitrary turn-on timing. Its high dV/dt immunity (>500 V/µs) prevents false triggering during voltage peaks. However, zero-crossing switching reduces EMI and inrush stress; the device fully supports either mode without hardware modification.

How does the crowbar overvoltage protection differ from a standard MOV-based solution?

The integrated crowbar clamps overvoltage *within the silicon* at ≥650 V, responding in nanoseconds with no leakage or aging. Unlike MOVs-which degrade after repeated surges and exhibit capacitance-induced EMI-the ACS108-6SUF-TR maintains consistent clamping performance over its full lifetime and eliminates external component count and board space.