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Home > Products > Discrete Semiconductor Products > Thyristors > TRIACs

STMicroelectronics ACS108-5SN

Name: ACS108-5SN
Brand: STMicroelectronics
SKU: ACS108-5SN
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: ACS108-5SN

Manufacturer:: STMicroelectronics

Category:: TRIACs

Package:: TO-261-4, TO-261AA

Datasheet:: ACS108-5SN.pdf

Description:: TRIAC SENS GATE 500V 0.8A SOT223

Quantity:: RFQ Add To RFQ list

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Inventory:9,773

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Product details

Overview

ACS108-5SN from STMicroelectronics is a monolithic AC line switch in SOT-223 package, designed for full-cycle ON/OFF control of low-power inductive/resistive loads (e.g., solenoids, valves, micro-motors) up to 0.8 A RMS at 230 VAC. It integrates a high-voltage clamping structure (V_CL = 600 V), gate-level shifter driver, and negative-gate-trigger logic. Its COM pin connects directly to PCB cooling pad, enabling multi-device thermal sharing.

For engineers reviewing the ACS108-5SN datasheet, ACS108-5SN pinout, ACS108-5SN application, or ACS108-5SN equivalent, this page delivers verified electrical specs, thermal resistance (R_th(j-t) = 25 °C/W), gate triggering behavior (I_GT < 10 mA), IEC61000-4-5 surge compliance (2 kV), and direct MCU interface capability without external protection.

Technical Context

The ACS108-5SN implements an integrated triac-like switching architecture with on-chip avalanche clamping and gate-level shifting. It operates with negative gate current sourced from the controller, eliminating gate kickback stress on MCUs. Its turn-off commutation handles inductive energy up to 20 mJ via internal clamping diode.

Thermal design centers on the SOT-223 tab (pin COM), which serves as both circuit common and thermal path-R_th(j-t) = 25 °C/W with 5 cm² copper. Electrical robustness includes dV/dt immunity ≥500 V/µs (T_j = 110 °C) and non-repetitive surge rating of 8 A at 60 Hz.

Key Specifications

Parameter	Value and Actual Design Meaning
V_DRM/V_RRM	500 V - Blocks full AC line peaks up to 230 VAC systems without external snubbers.
I_T(RMS)	0.8 A - Supports continuous resistive load switching at 75 °C ambient with SOT-223 mounting.
V_CL	600 V - Clamps inductive turn-off transients, absorbing up to 20 mJ energy internally.
I_GT	< 10 mA - Enables direct drive from standard MCU GPIO pins via simple series resistor.
R_th(j-t)	25 °C/W - Tab-to-PCB thermal resistance enables shared heatsinking across multiple devices on one copper pad.
dV/dt	≥500 V/µs - Prevents false triggering under fast line transients without external RC networks.
V_PP	2 kV - Withstands IEC61000-4-5 surge testing (150 Ω + 5 µH) without failure or degradation.

Pinout & Package

SOT-223 package with exposed metal tab (pin 3) serving as COM terminal and primary thermal path. Tab is electrically connected to pin 3 (COM) and must be soldered to ≥5 cm² copper area for rated current performance.

Pin/Terminal	Circuit Role	Design Meaning
G	Gate input	Negative-current trigger input; driven by MCU GPIO sinking ≤10 mA; no external protection required.
OUT	Switch output	Connects to load; voltage referenced to COM; handles full AC line voltage during off-state.
COM	Common reference	Electrical common and thermal tab; ties to neutral line and PCB copper cooling pad.
Tab	Thermal & electrical node	Internally bonded to COM pin; provides R_th(j-t) = 25 °C/W path to PCB copper.

Key Features

Feature	Design Value
Integrated clamping diode	Enables safe inductive load turn-off up to 20 mJ without external TVS or snubber components.
Gate-level shifter	Isolates MCU GPIO from AC line potential, eliminating gate kickback and simplifying isolation design.
Shared thermal pad compatibility	Multiple ACS108-5SN devices can mount on same copper area, reducing PCB thermal layout complexity.
IEC61000-4-5 compliant	Withstands 2 kV line surges per standard test configuration-no additional surge protection needed.
Direct MCU interface	Accepts standard 3.3 V/5 V GPIO drive with single series resistor; eliminates level-shifter ICs.

Applications

Washing Machine Door Lock Control

Dishwasher Solenoid Valve Actuation

Use Scenario: Precise timed engagement/disengagement of mechanical door lock during cycle phases.

IC Role / Device Role / Timing Role: AC line switch providing zero-crossing–free, full-cycle ON/OFF control of 0.15 A solenoid.

Use Value: Eliminates relay wear and acoustic noise while maintaining IEC61000-4-5 immunity in humid environments.

Use Scenario: On-demand hot water valve opening/closing in detergent dispensing subsystem.

IC Role / Device Role / Timing Role: High-dV/dt immune switch driving 0.2 A inductive valve with <10 ms turn-off delay.

Use Value: Achieves 0.8 A peak surge handling during cold-start inrush without external aids.

Refrigerator Defrost Heater Cycling

Compact Fan Speed Control in Cookware

Use Scenario: Periodic 5–10 minute activation of 0.6 A resistive heater during frost accumulation.

IC Role / Device Role / Timing Role: Thermally optimized AC switch operating at 75 °C ambient with shared SOT-223 tab cooling.

Use Value: Delivers 0.8 A RMS conduction with R_th(j-t) = 25 °C/W, avoiding thermal derating seen in TO-92 variants.

Use Scenario: Low-noise airflow modulation in countertop induction cooktop cooling system.

IC Role / Device Role / Timing Role: Resistive load switch controlling 0.3 A fan with <20 ms turn-off delay and >0.7 PF.

Use Value: Reduces component count by 80% vs. relay+driver solution while meeting EMC Class B limits.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
ACS108-5SA (TO-92)	Same die, TO-92 package; R_th(j-a) = 150 °C/W vs. 60 °C/W for SOT-223; lower I_T(RMS) = 0.3 A at 60 °C ambient.	Limited to low-power, space-constrained designs without forced cooling; unsuitable for multi-device thermal sharing.	Select only when board space prohibits SOT-223 or when single-device, low-current (<0.3 A) operation suffices.
ACS108-6SN	Higher blocking voltage (600 V V_DRM); identical SOT-223 package, pinout, and thermal specs.	Required for 277 VAC commercial lighting or industrial control where 500 V margin is insufficient.	Choose when line voltage exceeds 230 VAC RMS or transient margin must exceed 2 kV peak.

Compared with ACS108-5SA, the -5SN offers 2.5× better thermal performance and 2.7× higher RMS current capacity; versus ACS108-6SN, it trades 100 V blocking headroom for cost and footprint optimization in 230 VAC appliance designs.

Availability

ACS108-5SN is available at Aetrix Electronics and suitable for washing machine control modules, dishwasher valve actuation, and refrigerator defrost cycling requiring stable component supply across extended production lifecycles.

Supply support for ACS108-5SN 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, and smart power solutions for industrial and consumer markets.

The ACS™ AC line switch product line targets cost-sensitive, high-reliability appliance control-replacing electromechanical relays with monolithic, surge-immune solid-state alternatives for loads ≤0.8 A.

FAQ

What is the maximum ambient temperature for full 0.8 A RMS operation?

The ACS108-5SN supports 0.8 A RMS conduction at Tamb = 75 °C when mounted on ≥5 cm² copper (35 µm thick) per the datasheet's derating curve. Above 75 °C, current must be reduced linearly to 0 A at 125 °C junction limit. No forced air or heatsink is required within this envelope.

Can ACS108-5SN drive a 230 VAC, 0.5 A fan with power factor 0.3?

Yes-the ACS108-5SN drives such fans per Table 1 in the datasheet, classified as "Pump/Fan" with (dI/dt)_c < 0.3 A/ms and turn-off delay < 20 ms. Its 600 V clamping voltage safely absorbs the resulting inductive energy without external components.

Is a series gate resistor required, and what value is recommended?

Yes-a series gate resistor is mandatory to limit I_GT to <10 mA. For 5 V MCU GPIO, R_G = 470 Ω ensures ~9.5 mA peak current; for 3.3 V, R_G = 330 Ω yields ~9.1 mA. Resistor power rating must exceed 0.1 W peak pulse dissipation.

Does the COM pin require galvanic isolation from MCU ground?

No-COM connects to AC neutral and serves as the reference for G and OUT. The gate-level shifter inside the device isolates MCU GPIO from line potential; MCU ground may remain common with system low-voltage ground, provided layout avoids noise coupling into gate traces.

ACS108-5SN Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: ACS™/A.S.D®

Package/Case:: TO-261-4, TO-261AA

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Triac Type:: Logic - Sensitive Gate

Voltage - Off State:: 500 V

Current - On State (It (RMS)) (Max):: 800 mA

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

Current - Non Rep. Surge 50, 60Hz (Itsm):: 7.3A, 8A

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

Current - Hold (Ih) (Max):: 25 mA

Configuration:: Single

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: SOT-223

ACS108-5SN FAQ

1.How can I place an order for ACS108-5SN through Aetrix?

Please submit a Request for Quotation (RFQ) for ACS108-5SN 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 ACS108-5SN reliable?

The price and inventory of ACS108-5SN are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ACS108-5SN is usually 5 days.

3.What payment methods are accepted for ACS108-5SN?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ACS108-5SN transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for ACS108-5SN?

ACS108-5SN orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your ACS108-5SN 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 ACS108-5SN?

For technical support, including ACS108-5SN datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ACS108-5SN requirements.

6.How does Aetrix verify that ACS108-5SN is sourced from the original manufacturer or authorized distributors?

All ACS108-5SN 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 ACS108-5SN meets industry standards.

7.What is the process for return or replacement of ACS108-5SN?

All ACS108-5SN units undergo pre-shipment inspection (PSI). If there is an issue with ACS108-5SN, 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 ACS108-5SN part is unused and in its original packaging.

Return procedure for ACS108-5SN:

1.Submit a request within 90 days.

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

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