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Home > Products > Discrete Semiconductor Products > Thyristors > TRIACs

STMicroelectronics ACST410-8B

Name: ACST410-8B
Brand: STMicroelectronics
SKU: ACST410-8B
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ACST410-8B

Manufacturer:: STMicroelectronics

Category:: TRIACs

Package:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Datasheet:: ACST410-8B.pdf

Description:: TRIAC SENS GATE 800V 4A DPAK

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Product details

Overview

ACST410-8B from STMicroelectronics is a 4 A, 800 V insulated AC switch with integrated overvoltage clamping (V_CL ≥ 850 V), low gate trigger current (I_GT ≤ 10 mA), and high static dV/dt immunity (>1000 V/μs at T_j = 125 °C). It functions as a self-protected triac replacement in mains-connected AC load control circuits for home appliances and industrial systems.

For engineers reviewing the ACST410-8B datasheet, ACST410-8B pinout, ACST410-8B application, or ACST410-8B equivalent, key selection criteria include its IEC 61000-4-5 surge withstand capability (2 kV), TO-220FPAB insulation rating (2000 V_RMS), planar junction reliability, and direct MCU gate drive compatibility without external snubbers.

Technical Context

The ACST410-8B integrates a planar triac structure with an on-chip voltage-clamping crowbar circuit that activates during line transients exceeding V_CL, enabling safe conduction of surge energy through the load. Its gate-triggering threshold remains stable across –40 to +125 °C, with I_GT guaranteed ≤10 mA at 25 °C and ≤15 mA at 125 °C.

It operates in all four quadrants with symmetrical blocking (V_DRM/V_RRM = 800 V), supports inductive loads up to 4 A RMS without external snubbers, and maintains dV/dt immunity ≥500 V/μs even at elevated junction temperature (125 °C) with gate open.

Key Specifications

Parameter	Value and Actual Design Meaning
I_T(RMS)	4 A - Sustains continuous sinusoidal load current up to 4 A at T_c = 102 °C (TO-220FPAB)
V_DRM/V_RRM	800 V - Blocks 800 V peak AC line voltage in both directions, suitable for 230 V_RMS mains with safety margin
I_GT	≤10 mA - Enables direct drive from low-power MCU GPIO via single series resistor (e.g., 1 kΩ @ 3.3 V)
V_CL	≥850 V - Clamps transient overvoltages above this threshold, eliminating need for external MOVs or TVS diodes
dV/dt (static)	≥1000 V/μs - Immune to fast EFT bursts per IEC 61000-4-4 without false triggering
R_th(j-c)	4.6 °C/W - Enables thermal design with heatsink interface for sustained 4 A operation in TO-220FPAB package
V_TM	≤1.7 V - Low on-state voltage drop reduces conduction losses and heat generation at full load

Pinout & Package

DPAK (TO-220FPAB-compatible insulated package) with three terminals: COM (common cathode/anode reference), OUT (main output terminal), and G (gate). The package provides reinforced insulation rated at 2000 V_RMS for 60 seconds per UL E81734.

Pin/Terminal	Circuit Role	Design Meaning
COM	Common reference terminal	Shared connection point for internal triac cathode/anode; referenced to load return path and gate drive ground
OUT	Main output terminal	Carries full load current; connected to AC line or load side depending on topology (e.g., high-side or low-side switching)
G	Gate control input	Triggers conduction when pulsed with ≥10 mA; polarity-insensitive due to quad-quadrant triac architecture

Key Features

Feature	Design Value
Integrated overvoltage clamping	V_CL ≥ 850 V enables compliance with IEC 61000-4-5 (2 kV surge) without external protection components
High noise immunity	Static dV/dt > 1000 V/μs ensures robust operation in electrically noisy appliance environments (e.g., compressor startup)
Low gate drive requirement	I_GT ≤ 10 mA allows direct interfacing with 3.3 V or 5 V MCUs using only a current-limiting resistor
Insulated TO-220FPAB package	2000 V_RMS isolation meets UL E81734 and eliminates need for creepage/clearance PCB redesign
No-snubber inductive switching	Supports 4 A inductive loads (e.g., universal motors, compressors) without external RC snubber networks

Applications

Washing Machine Drum Motor Control

Refrigerator Compressor Drive

Use Scenario: Bidirectional speed and direction control of universal AC motors in washing machine drum assemblies.

IC Role / Device Role / Timing Role: AC mains switch replacing mechanical relays and standard triacs; handles phase-angle or zero-cross switching under MCU timing control.

Use Value: Eliminates relay wear-out and reduces EMI vs. standard triacs due to built-in dV/dt immunity and clamping-enabling quieter, longer-life motor control.

Use Scenario: Start/run control of hermetic compressors in refrigeration systems with high inrush currents.

IC Role / Device Role / Timing Role: High-reliability AC switch managing full-line voltage to compressor windings; triggered by thermostat or inverter logic.

Use Value: Withstands compressor turn-off inductive spikes without snubber, and survives repeated IEC 61000-4-5 surges-reducing field failure rates in harsh grid environments.

Air Conditioner Fan Motor Switching

Industrial HVAC Blower Control

Use Scenario: On/off and staged power control of PSC or shaded-pole fan motors in residential air conditioners.

IC Role / Device Role / Timing Role: Solid-state alternative to electromechanical contactors; driven by microcontroller PWM or logic signals.

Use Value: 4 A RMS rating and 800 V blocking support continuous fan operation at 230 VAC; insulation prevents ground-loop faults in metal chassis designs.

Use Scenario: Medium-power AC load switching in programmable HVAC controllers for commercial buildings.

IC Role / Device Role / Timing Role: Mains-rated solid-state switch interfaced with PLC outputs or isolated digital drivers for blower and damper actuation.

Use Value: UL-certified 2000 V_RMS isolation simplifies safety certification; low I_GT enables direct optocoupler output drive without buffer stages.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ACST435-8B	I_GT ≤ 35 mA (higher gate drive requirement); identical V_DRM, V_CL, and package	Better suited for noisy industrial environments where higher gate immunity reduces false triggering risk	Select when system-level EMI exceeds 1000 V/μs or gate drive voltage is unstable
ACS108-8SN	Lower I_T(RMS) = 1.2 A; same 800 V rating and DPAK package; no integrated clamping (requires external MOV)	Limited to light-duty loads (e.g., small solenoids, lamps); not suitable for compressor or motor inrush	Choose only for cost-sensitive, low-current applications where external protection is acceptable

Compared with ACST435-8B and ACS108-8SN, the ACST410-8B uniquely balances ultra-low gate drive (≤10 mA), full 4 A load capability, and self-contained overvoltage protection-making it optimal for MCU-driven appliance motor control where board space, BOM count, and reliability are critical.

Availability

ACST410-8B is available at Aetrix Electronics and suitable for washing machine motor control, refrigerator compressor drive, and HVAC blower switching requiring stable component supply and long-term industrial lifecycle support.

Supply support for ACST410-8B 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 management, analog, MEMS, and microcontrollers for industrial, automotive, and consumer markets.

The ACST4 series belongs to ST's ACS/ACST family of overvoltage-protected AC switches, designed specifically to replace electromechanical relays and unprotected triacs in home appliance motor control and industrial AC load switching.

FAQ

What is the maximum continuous load current the ACST410-8B can switch?

The ACST410-8B supports 4 A RMS continuous current when mounted on a heatsink with case temperature maintained at ≤102 °C (per TO-220FPAB derating curve). At ambient conditions with minimal copper area, derating applies-e.g., ~1.5 A in free-air convection with DPAK package. Thermal design must respect R_th(j-c) = 4.6 °C/W and maximum T_j = 125 °C.

Does the ACST410-8B require an external snubber circuit for inductive loads?

No. The ACST410-8B is specifically characterized to drive inductive loads up to 4 A RMS without external snubbers, thanks to its high commutation robustness (dI/dt ≥ 5 A/ms) and integrated overvoltage clamping. This is validated per IEC 61000-4-5 testing with 2 kV surges and inductive test loads (L = 2 µH, R = 23 Ω).

Can the ACST410-8B be directly driven by a 3.3 V microcontroller GPIO?

Yes. With I_GT ≤ 10 mA and V_GT ≤ 1.0 V, a 3.3 V MCU GPIO driving through a 220 Ω series resistor delivers ~10.5 mA-sufficient for reliable triggering across temperature. Gate current must be applied for ≥10 µs, and the MCU output must tolerate 1.7 V back-emf during conduction.

How does the ACST410-8B's overvoltage protection differ from a standard MOV-based solution?

Unlike external MOVs-which absorb energy as heat and degrade over time-the ACST410-8B uses active crowbar clamping: when V_OUT–COM exceeds V_CL (≥850 V), it latches ON for <10 ms, diverting surge current through the load. After zero-crossing, it recovers full blocking capability-enabling repeatable, non-degrading surge protection per IEC 61000-4-5.

ACST410-8B Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: ACS™/A.S.D®

Package/Case:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Packaging:: Tube

Product Status:: Obsolete

Triac Type:: Logic - Sensitive Gate

Voltage - Off State:: 800 V

Current - On State (It (RMS)) (Max):: 4 A

Voltage - Gate Trigger (Vgt) (Max):: 1 V

Current - Non Rep. Surge 50, 60Hz (Itsm):: 30A, 32A

Current - Gate Trigger (Igt) (Max):: 10 mA

Current - Hold (Ih) (Max):: 20 mA

Configuration:: Single

Operating Temperature:: -40°C ~ 125°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: DPAK

ACST410-8B FAQ

1.How can I place an order for ACST410-8B through Aetrix?

Please submit a Request for Quotation (RFQ) for ACST410-8B on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.

2.Are the price and stock information for ACST410-8B reliable?

The price and inventory of ACST410-8B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ACST410-8B is usually 5 days.

3.What payment methods are accepted for ACST410-8B?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ACST410-8B transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ACST410-8B?

ACST410-8B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ACST410-8B order is processed, you will receive an email with the shipment details and tracking number.

Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.

5.How can I obtain technical support or documentation for ACST410-8B?

For technical support, including ACST410-8B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ACST410-8B requirements.

6.How does Aetrix verify that ACST410-8B is sourced from the original manufacturer or authorized distributors?

All ACST410-8B products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that ACST410-8B meets industry standards.

7.What is the process for return or replacement of ACST410-8B?

All ACST410-8B units undergo pre-shipment inspection (PSI). If there is an issue with ACST410-8B, returns or replacements are accepted under the following conditions:

1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.

2.The issue is reported within 90 days of delivery.

3.The ACST410-8B part is unused and in its original packaging.

Return procedure for ACST410-8B:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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