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Home > Products > Discrete Semiconductor Products > Thyristors > TRIACs

STMicroelectronics ACST8-8CG-TR

Name: ACST8-8CG-TR
Brand: STMicroelectronics
SKU: ACST8-8CG-TR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ACST8-8CG-TR

Manufacturer:: STMicroelectronics

Category:: TRIACs

Package:: TO-263-3, D2PAK (2 Leads + Tab), TO-263AB

Datasheet:: ACST8-8CG-TR.pdf

Description:: TRIAC 800V 8A D2PAK

Quantity:: RFQ Add To RFQ list

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Product details

Overview

ACST8-8CG-TR from STMicroelectronics is an overvoltage-protected AC power switch built on ASD™ triac technology, designed for bidirectional phase-angle control of induction motors in home appliances. It delivers 8A RMS on-state current at T_CASE = 90 °C, withstands ±800 V repetitive peak off-state voltage, and features snubberless turn-off commutation (dI/dt)_c ≥ 4.5 A/ms - enabling direct drive of washing machine bi-rotational motors without external snubbers.

For engineers reviewing the ACST8-8CG-TR datasheet, ACST8-8CG-TR pinout, ACST8-8CG-TR application, or ACST8-8CG-TR equivalent, this device is selected for robust line-transient immunity (IEC61000-4-5 compliant), high static dV/dt (>750 V/µs), low gate trigger current (<30 mA), and D2PAK-packaged thermal performance (R_th(j-c) = 2.5 °C/W) in space-constrained motor control PCBs.

Technical Context

The ACST8-8CG-TR integrates a planar triac structure with internal avalanche clamping to absorb inductive turn-off energy and suppress line transients up to 2 kV peak pulse voltage per IEC61000-4-5. Its gate-triggering logic requires negative current flow out of the G pin when driven by low-voltage controllers, supporting simple resistor-based triggering.

It operates across –40 °C to +125 °C junction temperature, sustains 80 A non-repetitive surge current (t_p = 20 ms), and maintains stable latching (I_L ≤ 70 mA) and holding (I_H ≤ 40 mA) currents over temperature - critical for reliable full-cycle ON/OFF and phase-control operation in compressor and tumble dryer motor drives.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DRM/V_RRM	±800 V - blocks full AC mains surges including 240 V RMS + 2 kV IEC61000-4-5 transients without external clamping
I_T(RMS)	8 A at T_CASE = 90 °C - supports continuous motor loads up to ~1.8 kW (240 V) without heatsink derating
(dI/dt)_c	≥4.5 A/ms - enables snubberless turn-off for inductive loads like refrigerator compressors and washing machine motors
Static dV/dt	>750 V/µs at T_j = 125 °C - prevents false triggering from EMI or fast line transients in noisy appliance environments
I_GT	<30 mA at V_OUT = 12 V - compatible with standard MCU GPIO or optocoupler outputs without gate driver ICs
V_CL	1200 V typ. at I_CL = 1 mA - clamps turn-off energy internally, eliminating need for MOVs or TVS diodes
R_th(j-c)	2.5 °C/W - D2PAK package delivers superior thermal transfer to PCB copper, reducing case temperature rise under load

Pinout & Package

D2PAK (TO-263) surface-mount package with isolated tab; thermally enhanced for PCB conduction cooling. Pin 1 = COM (common reference), Pin 2 = OUT (load output), Pin 3 = G (gate input). Tab is electrically connected to COM.

Pin/Terminal	Circuit Role	Design Meaning
COM (Pin 1)	Common reference terminal	Connected to AC neutral or common return path; electrically tied to metal tab for thermal and electrical grounding
OUT (Pin 2)	Switched AC output	Drives inductive load (e.g., motor winding); carries full RMS and surge current; referenced to COM
G (Pin 3)	Gate control input	Receives negative trigger current (outflow) from controller; low I_GT allows direct MCU/opto drive

Key Features

Feature	Design Value
Avalanche-controlled overvoltage protection	Internal clamping at V_CL ≈ 1200 V eliminates need for external MOVs or RC snubbers in EN61000-4-5-compliant designs
Snubberless turn-off commutation	(dI/dt)_c ≥ 4.5 A/ms ensures clean zero-crossing interruption of 8 A inductive motor current without oscillation or re-strike
High noise immunity	Static dV/dt > 750 V/µs at 125 °C prevents spurious turn-on from EMI in washing machine control boards near motors and relays
Planar triac structure	Enables stable off-state leakage (<1 µA at 125 °C) and high reliability over 10+ year appliance lifetimes
Low gate trigger threshold	I_GT < 30 mA at 25 °C allows use of cost-effective 5 V or 3.3 V microcontrollers without level-shifting or buffer stages

Applications

Washing Machine Bi-Rotational Drive

Refrigerator Compressor Control

Use Scenario: Controlling direction and speed of induction motor in drum washers using dual-phase-shift capacitor topology.

IC Role / Device Role / Timing Role: AC line-switching power device performing full-cycle ON/OFF and phase-angle control on motor windings.

Use Value: Eliminates snubber components and reduces BOM count by integrating transient clamping and high dI/dt turn-off capability.

Use Scenario: Cycling compressor motor in frost-free refrigerators with frequent start-stop cycles under varying ambient temperatures.

IC Role / Device Role / Timing Role: High-reliability AC switch handling inrush current and inductive kickback during compressor de-energization.

Use Value: Withstands 85 A surge (16.7 ms) and maintains stable latching/holding behavior from –40 °C to +125 °C junction range.

Air Conditioning Fan Motor

Tumble Dryer Heating & Drum Control

Use Scenario: Modulating airflow via phase-controlled induction fan motor in split-system AC units operating continuously at high ambient temps.

IC Role / Device Role / Timing Role: Line-synchronized AC power switch managing motor torque and speed without auxiliary control ICs.

Use Value: R_th(j-c) = 2.5 °C/W in D2PAK enables direct PCB copper cooling, avoiding discrete heatsinks in compact indoor units.

Use Scenario: Dual-switch configuration driving heating element and bi-directional drum motor in vented dryers with high thermal cycling.

IC Role / Device Role / Timing Role: Overvoltage-protected AC switch handling combined resistive (heater) and inductive (motor) loads.

Use Value: V_DRM/V_RRM = ±800 V and 2 kV transient rating ensure survival during heater fault events and motor stall conditions.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ACS108-6S	Lower V_DRM = 600 V; higher I_T(RMS) = 10 A; TO-252 package; no integrated avalanche clamping	Suitable for 120 V markets only; requires external MOV for IEC61000-4-5 compliance	Select when higher RMS current is needed and line voltage is ≤120 V RMS with controlled surge environment.
ACST12-10H	Higher V_DRM = 1000 V; same D2PAK package; I_T(RMS) = 12 A; (dI/dt)_c = 5 A/ms	Supports 3-phase industrial loads and 400 V systems; larger die increases thermal mass but raises gate drive requirement	Choose for future-proofing in multi-voltage platforms or where extended surge margin beyond 2 kV is required.

Compared with ACS108-6S, ACST8-8CG-TR provides essential 800 V blocking and integrated clamping for global 230/240 V mains - while ACST12-10H trades higher voltage/current headroom for increased gate drive demand and cost, making ACST8-8CG-TR optimal for cost-sensitive, space-constrained 8 A appliance motor control.

Availability

ACST8-8CG-TR is available at Aetrix Electronics and suitable for washing machine motor drives, refrigerator compressor controls, and air conditioning fan modules requiring stable component supply across global appliance production programs.

Supply support for ACST8-8CG-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, specializing in power, analog, MEMS, and microcontroller technologies for industrial and consumer applications.

The AC Switch (ASD™) family - including ACST8-8CG-TR - was engineered specifically for robust, snubberless AC motor control in white goods, targeting high reliability, reduced system cost, and compliance with international surge immunity standards.

FAQ

What is the maximum allowable junction temperature for continuous operation?

The ACST8-8CG-TR has a specified operating junction temperature range of –40 °C to +125 °C. For continuous RMS current operation at 8 A, the case temperature must be maintained at ≤90 °C per datasheet derating curves - achievable in D2PAK with ≥1 cm² copper pad and natural convection.

Can ACST8-8CG-TR replace a standard triac in existing designs?

Yes - it is pin-compatible with industry-standard D2PAK triacs (e.g., BTB16-800BRG), but requires verification of gate drive polarity: ACST8-8CG-TR triggers with negative current out of the G pin, unlike conventional triacs that require positive gate current into G.

Does this device require a heat sink in typical appliance applications?

No external heat sink is required when mounted on ≥1 cm² of 2-oz copper with thermal vias; its R_th(j-c) = 2.5 °C/W and R_th(j-a) = 45 °C/W (on 1 cm² pad) enable 8 A operation at ambient ≤50 °C with natural convection - validated in washing machine control board layouts.

How does the internal avalanche clamping protect against IEC61000-4-5 surges?

During a 2 kV line surge, the device enters controlled avalanche breakdown at V_CL ≈ 1200 V, diverting transient energy into the silicon junction rather than allowing destructive voltage overshoot - verified for 10 polarity-reversed surges per IEC61000-4-5 test conditions without parameter shift.

ACST8-8CG-TR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: ASD™

Package/Case:: TO-263-3, D2PAK (2 Leads + Tab), TO-263AB

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Triac Type:: Standard

Voltage - Off State:: 800 V

Current - On State (It (RMS)) (Max):: 8 A

Voltage - Gate Trigger (Vgt) (Max):: 1.5 V

Current - Non Rep. Surge 50, 60Hz (Itsm):: 80A, 85A

Current - Gate Trigger (Igt) (Max):: 30 mA

Current - Hold (Ih) (Max):: 40 mA

Configuration:: Single

Operating Temperature:: -

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: D2PAK

ACST8-8CG-TR FAQ

1.How can I place an order for ACST8-8CG-TR through Aetrix?

Please submit a Request for Quotation (RFQ) for ACST8-8CG-TR 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 ACST8-8CG-TR reliable?

The price and inventory of ACST8-8CG-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ACST8-8CG-TR is usually 5 days.

3.What payment methods are accepted for ACST8-8CG-TR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ACST8-8CG-TR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ACST8-8CG-TR?

ACST8-8CG-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ACST8-8CG-TR 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 ACST8-8CG-TR?

For technical support, including ACST8-8CG-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ACST8-8CG-TR requirements.

6.How does Aetrix verify that ACST8-8CG-TR is sourced from the original manufacturer or authorized distributors?

All ACST8-8CG-TR 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 ACST8-8CG-TR meets industry standards.

7.What is the process for return or replacement of ACST8-8CG-TR?

All ACST8-8CG-TR units undergo pre-shipment inspection (PSI). If there is an issue with ACST8-8CG-TR, 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 ACST8-8CG-TR part is unused and in its original packaging.

Return procedure for ACST8-8CG-TR:

1.Submit a request within 90 days.

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

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