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Home > Products > Discrete Semiconductor Products > Thyristors > TRIACs

STMicroelectronics ACST4-7CFP

Name: ACST4-7CFP
Brand: STMicroelectronics
SKU: ACST4-7CFP
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ACST4-7CFP

Manufacturer:: STMicroelectronics

Category:: TRIACs

Package:: TO-220-3 Full Pack

Datasheet:: ACST4-7CFP.pdf

Description:: TRIAC 700V 4A TO220FP

Quantity:: RFQ Add To RFQ list

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Product details

Overview

ACST4-7CFP from STMicroelectronics is a 700 V, 4 A AC power switch in TO-220FPAB package, featuring integrated gate driver, avalanche-controlled clamping (V_CL = 1100 V), and high noise immunity (dV/dt > 500 V/µs). It directly interfaces with microcontrollers to control inductive/resistive loads such as dishwasher spray pumps and air-conditioner fans without external snubbers or overvoltage protection.

For engineers reviewing the ACST4-7CFP datasheet, ACST4-7CFP pinout, ACST4-7CFP application, or ACST4-7CFP equivalent, this device offers verified IEC 61000-4-5 transient ruggedness, gate-trigger current of 25 mA (QI–QIII), on-state resistance ≤100 mΩ at 125 °C, and thermal resistance R_th(j-c) = 4.6 °C/W - critical for reliable AC line switching in space-constrained industrial and appliance designs.

Technical Context

The ACST4-7CFP implements an ASD™-based Triac structure with monolithically integrated voltage clamping, enabling safe turn-off energy absorption during inductive load commutation. Its planar junction technology ensures stable off-state leakage (<500 µA at 125 °C) and high static dV/dt immunity (>500 V/µs at T_j = 110 °C).

It operates across -30 to +125 °C junction temperature, supports full-cycle sine-wave conduction at 50–60 Hz, and sustains non-repetitive 2 kV line transients per IEC 61000-4-5 (R = 150 Ω, L = 10 µH). Gate triggering is validated for all four quadrants (QI–QIII), with latching current ≤60 mA and holding current ≤35 mA at 25 °C.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DRM/V_RRM	±700 V - Withstands repetitive AC line peaks up to 495 V RMS with safety margin for surge events.
I_T(RMS)	4 A at T_c = 100 °C - Sustains continuous load current in TO-220FPAB package without heatsink derating beyond 100 °C case temp.
I_TSM	33 A (60 Hz, 20 ms) - Handles motor startup surges and compressor inrush without failure.
I_GT	<25 mA (QI–QIII, T_j = 25 °C) - Compatible with standard MCU GPIOs via simple series resistor (no buffer needed).
V_CL	1100 V typ. - Clamps inductive turn-off transients below destructive levels, eliminating need for external MOVs or RC snubbers.
dV/dt	>500 V/µs (static, T_j = 110 °C) - Resists false triggering from EMI or fast-rising line noise in noisy appliance environments.
R_th(j-c)	4.6 °C/W - Enables predictable thermal design with direct tab-to-heatsink mounting in compact enclosures.

Pinout & Package

ACST4-7CFP uses TO-220FPAB package: insulated plastic body with metal tab (pin OUT), 3-pin through-hole layout, 2.4 g weight, UL94 V0 epoxy, and 10 s soldering tolerance at 260 °C.

Pin/Terminal	Circuit Role	Design Meaning
OUT	Switch output terminal / high-side load connection	Connected directly to load; metal tab is electrically active and must be isolated from chassis unless referenced to neutral.
COM	Common reference / neutral-side connection	Reference node for gate drive and load return; tied to AC line neutral in basic configurations.
G	Gate control input	Sinks trigger current (≤25 mA); driven low by MCU GPIO to initiate conduction in all quadrants.

Key Features

Feature	Design Value
Integrated clamping protection	V_CL = 1100 V enables compliance with IEC 61000-4-5 without external components.
Direct microcontroller interface	I_GT ≤25 mA allows GPIO-level triggering without level-shifting or buffering circuitry.
High commutation robustness	(dI/dt)_c ≥2.5 A/ms at V_out = 300 V ensures reliable turn-off under high-inductance loads like fan motors.
Planar junction reliability	Leakage <500 µA at 125 °C and T_j range –30 to +125 °C support long-term operation in sealed appliances.
No external snubber required	Validated for 4 A inductive loads (e.g., dishwasher pumps) with no added RC network - reduces BOM count and PCB area.

Applications

Dishwasher Spray Pump Control

Air-Conditioner Fan Drive

Use Scenario: Precise on/off cycling of 120–240 VAC spray pump motor in residential dishwashers.

IC Role / Device Role / Timing Role: AC line switch replacing mechanical relay; handles 4 A resistive-inductive load with zero-crossing–independent triggering.

Use Value: Eliminates relay wear-out, reduces acoustic noise, and withstands 2 kV IEC 61000-4-5 surges common in kitchen power environments.

Use Scenario: Speed-controlled or staged on/off operation of shaded-pole or PSC fan motors in split-system AC units.

IC Role / Device Role / Timing Role: Solid-state AC switch interfacing directly with HVAC controller MCU; manages inrush and steady-state current without snubber.

Use Value: Achieves >100,000 cycle lifetime vs. ~50,000 for relays, while maintaining dV/dt immunity >500 V/µs in high-EMI HVAC enclosures.

Induction Cooktop Power Stage

Smart Plug Load Switching

Use Scenario: Secondary AC switching stage controlling auxiliary heating elements or cooling fans in induction cooktops.

IC Role / Device Role / Timing Role: High-noise-immunity AC switch placed downstream of main Triac/SCR stage; handles 4 A auxiliary loads.

Use Value: Survives repeated 2 kV transients induced by primary coil switching, with clamping action limiting stress on downstream logic.

Use Scenario: Remote-controllable AC outlet in smart home plugs rated for 4 A resistive loads (e.g., lamps, small appliances).

IC Role / Device Role / Timing Role: Primary load switch enabling energy monitoring and scheduling via ESP32 or similar host MCU.

Use Value: Reduces component count by integrating clamping and gate drive, meeting UL 60730 Class A requirements without external TVS or optocoupler isolation.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ACST4-7CB	DPAK package (R_th(j-c) = 2.6 °C/W), lower I_GT (10 mA), same V_DRM/I_T(RMS).	Better thermal performance in surface-mount layouts; requires PCB copper area for heat dissipation.	Select when board space permits SMT assembly and higher thermal conductivity is prioritized over through-hole mounting.
ACS108-7SN	8 A RMS rating, SO-8 package, I_GT = 15 mA, V_CL = 1000 V, no integrated clamping diode.	Higher current capacity but requires external clamping for IEC 61000-4-5 compliance.	Choose for 6–8 A loads where external protection is acceptable and SO-8 footprint is preferred.

Compared with ACST4-7CB and ACS108-7SN, the ACST4-7CFP uniquely combines TO-220FPAB's mechanical robustness, 25 mA gate drive compatibility, and monolithic 1100 V clamping - making it optimal for through-hole appliance control boards needing drop-in reliability without redesign.

Availability

ACST4-7CFP is available at Aetrix Electronics and suitable for dishwasher control modules, HVAC fan drivers, and smart plug designs requiring stable component supply, long-lifecycle availability, and IEC 61000-4-5-compliant AC switching.

Supply support for ACST4-7CFP 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 silicon solutions for automotive, industrial, and consumer markets since 1987.

The ACST4 Series belongs to ST's ASD™ AC power switch product line, engineered specifically for solid-state replacement of electromechanical relays in home appliance and industrial control systems demanding high transient immunity and simplified drive architecture.

FAQ

What is the maximum ambient temperature for ACST4-7CFP in natural convection?

At natural convection on FR4 PCB with 0.5 cm² copper under tab, ACST4-7CFP delivers 4 A RMS up to 75 °C ambient (Fig. 2-2). Above that, derating applies: 3.5 A at 85 °C, 2.8 A at 100 °C. Thermal performance assumes TO-220FPAB tab mounted to heatsink or large copper pour.

Does ACST4-7CFP require a heatsink for 4 A continuous operation?

Yes - at T_c = 100 °C (per Absolute Ratings table), the device requires heatsinking or ≥10 cm² copper area to maintain junction temperature ≤125 °C. Without heatsink, max continuous current drops to ~2.2 A in still air (based on R_th(j-a) ≈ 60 °C/W).

Can ACST4-7CFP replace a mechanical relay in a 240 VAC dishwasher pump circuit?

Yes - it replaces SPST relays driving 4 A inductive loads. Verified performance includes 2 kV IEC 61000-4-5 surge survival, 30 A/20 ms surge rating, and no contact bounce or arcing. Gate drive requires only a 330 Ω resistor from 3.3 V/5 V MCU GPIO.

Is the metal tab (OUT pin) electrically isolated in TO-220FPAB package?

No - the metal tab is internally connected to the OUT terminal and is not insulated. It must be mounted on an isolated heatsink or kept clear of grounded chassis. Electrical isolation requires insulating kit (mica washer + nylon screw) or use of DPAK variants like ACST4-7CB-TR.

ACST4-7CFP Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3 Full Pack

Packaging:: Tube

Product Status:: Obsolete

Triac Type:: Standard

Voltage - Off State:: 700 V

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

Voltage - Gate Trigger (Vgt) (Max):: 1.1 V

Current - Non Rep. Surge 50, 60Hz (Itsm):: 30A, 33A

Current - Gate Trigger (Igt) (Max):: 25 mA

Current - Hold (Ih) (Max):: 35 mA

Configuration:: Single

Operating Temperature:: -30°C ~ 125°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220FP

ACST4-7CFP FAQ

1.How can I place an order for ACST4-7CFP through Aetrix?

Please submit a Request for Quotation (RFQ) for ACST4-7CFP 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 ACST4-7CFP reliable?

The price and inventory of ACST4-7CFP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ACST4-7CFP is usually 5 days.

3.What payment methods are accepted for ACST4-7CFP?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ACST4-7CFP transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ACST4-7CFP?

ACST4-7CFP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ACST4-7CFP 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 ACST4-7CFP?

For technical support, including ACST4-7CFP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ACST4-7CFP requirements.

6.How does Aetrix verify that ACST4-7CFP is sourced from the original manufacturer or authorized distributors?

All ACST4-7CFP 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 ACST4-7CFP meets industry standards.

7.What is the process for return or replacement of ACST4-7CFP?

All ACST4-7CFP units undergo pre-shipment inspection (PSI). If there is an issue with ACST4-7CFP, 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 ACST4-7CFP part is unused and in its original packaging.

Return procedure for ACST4-7CFP:

1.Submit a request within 90 days.

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

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