STMicroelectronics ACST210-8BTR

Overview

ACST210-8BTR from STMicroelectronics is an overvoltage-protected AC switch (Triac-based A.S.D.® discrete) designed for direct microcontroller-driven AC on/off control of inductive loads up to 2 A RMS. It features integrated overvoltage crowbar clamping (VCL ≥ 850 V), high static dV/dt immunity (>500 V/µs at 125 °C), and low gate trigger current (IGT ≤ 10 mA), enabling robust operation in appliance motor control and industrial solenoid switching without external snubbers or transient protection.

For engineers reviewing the ACST210-8BTR datasheet, ACST210-8BTR pinout, ACST210-8BTR application, or ACST210-8BTR equivalent, this device is selected for IEC 61000-4-4/4-5-compliant AC load switching where self-protected turn-off energy absorption, logic-level gate drive compatibility, and DPAK thermal performance (Rth(j-c) = 4.5 °C/W) are critical design requirements.

Technical Context

The ACST210-8BTR integrates a planar Triac structure with a monolithically embedded high-voltage clamping device that activates during inductive turn-off transients or line surges, folding the device into conduction to safely dissipate energy through the load. Its gate sensitivity (IGT ≤ 10 mA) is maintained while achieving dV/dt immunity exceeding 500 V/µs at junction temperature up to 125 °C - five to ten times higher than conventional sensitive Triacs.

This behavior stems from proprietary A.S.D.® (Application Specific Discrete) process technology, which optimizes the trade-off between gate sensitivity and commutation robustness. The device operates in quadrants I, II, and III, supports full-cycle sine-wave conduction, and recovers blocking capability after surge events at the next zero-current crossing - a key distinction from sacrificial TVS-based protection schemes.

Key Specifications

Pinout & Package

DPAK (TO-252) surface-mount package with isolated tab (no internal connection); thermally optimized for PCB copper area mounting (SCU = 0.5 cm² recommended).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ACS108-6SN and BTB12-600CW, the ACST210-8BTR uniquely combines 2 A rating, DPAK footprint, logic-compatible gate drive, and monolithic overvoltage crowbar - reducing component count and qualification effort for IEC-compliant appliance designs.

Availability

ACST210-8BTR is available at Aetrix Electronics and suitable for home appliance motor control, industrial solenoid actuation, smart lighting interfaces, and commercial fan speed control requiring stable component supply across multi-year production programs.

Supply support for ACST210-8BTR 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, specializing in power discrete devices, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.

The ACST2 series belongs to ST's A.S.D.® (Application Specific Discrete) portfolio, engineered specifically for robust, snubberless AC load switching in cost-sensitive, high-volume appliance and industrial control applications.

FAQ

What is the maximum continuous load current the ACST210-8BTR can switch?

The ACST210-8BTR is rated for 2 A RMS continuous on-state current when mounted on a PCB with 0.5 cm² copper area and case temperature maintained at ≤110 °C. Derating applies above this temperature - e.g., ~1.6 A at TC = 125 °C per Figure 3. It is not rated for DC loads or rectified outputs.

Does the ACST210-8BTR require a heat sink in typical applications?

No external heat sink is required for 2 A RMS operation if the DPAK package is soldered to ≥0.5 cm² of 35 µm copper on FR4 PCB (Rth(j-a) = 70 °C/W). Thermal performance improves with larger copper areas - doubling copper area reduces Rth(j-a) by ~25%. Forced air or metal-core PCBs further extend capability.

Can the ACST210-8BTR replace a mechanical relay directly?

Yes - it replaces SPST AC relays driving resistive or inductive loads ≤2 A, offering silent operation, no contact bounce, and >10× longer lifetime. Unlike relays, it requires zero-crossing control logic to minimize inrush and EMI, and must be protected from reverse polarity (not bidirectional like a Triac in full-wave mode).

How does the overvoltage crowbar function differ from a standard TVS diode?

The crowbar is monolithic and active: when voltage exceeds VCL (~850 V), the device latches into low-impedance conduction for <10 ms, shunting surge energy through the load rather than clamping to a fixed voltage. This avoids TVS thermal failure modes and enables safe dissipation of higher-energy transients - verified per IEC 61000-4-5 test waveforms.