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STMicroelectronics ACS120-7ST
- Part No.:
- ACS120-7ST
- Manufacturer:
- STMicroelectronics
- Category:
- TRIACs
- Package:
- TO-220-3
- Datasheet:
-
ACS120-7ST.pdf
- Description:
- TRIAC SENS GATE 700V 2A TO220
- Quantity:
- Payment:
- Shipping:
Inventory:1,936
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Product details
Overview
ACS120-7ST from STMicroelectronics is a high-noise-immunity AC line switch in TO-220AB package, designed for direct microcontroller-driven static switching of inductive/resistive loads up to 2 A RMS. It features ±700 V blocking voltage, 1100 V avalanche clamping, <10 mA gate trigger current, and integrated gate-level shifter driver. Used in appliance motor/valve control where snubber-free turn-off and IEC 61000-4-5 compliance are required.
For engineers reviewing the ACS120-7ST datasheet, ACS120-7ST pinout, ACS120-7ST application, or ACS120-7ST equivalent, key selection criteria include dV/dt immunity (>500 V/µs), clamping voltage (1100 V typ), thermal resistance (2.6 °C/W j-to-tab), gate polarity (negative-triggered), and compatibility with 25–125 °C junction operation in washing machines, dishwashers, and HVAC systems.
Technical Context
The ACS120-7ST implements ST's ASD™ architecture, integrating a high-voltage clamping diode and gate-level shifter to isolate digital controllers from mains-referenced switching paths. Its negative-gate-triggering logic enables direct connection to MCU GPIO without level-shifting circuitry.
It sustains 2 kV non-repetitive line pulses per IEC 61000-4-5 using internal avalanche energy absorption, eliminating external varistors or RC snubbers. Turn-off commutation is managed via linear current decay through the clamping section, dissipating up to 10 mJ inductive energy safely.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDRM / VRRM | ±700 V - blocks full AC line peaks including surge margins in 230 VAC systems |
| IT(RMS) | 2 A at Tc = 115 °C - supports continuous load current for solenoids, fans, and defrost heaters |
| VCL (typ) | 1100 V - clamps inductive turn-off transients without external components |
| dV/dt (min) | 500 V/µs - prevents false triggering in noisy appliance environments |
| IGT (max) | 10 mA - compatible with standard MCU GPIO drive capability |
| Rd (max) | 200 mΩ at Tj = 125 °C - limits conduction loss to <0.8 W at 2 A RMS |
| Rth(j-l) | 2.6 °C/W - enables efficient heatsinking on shared cooling pads in multi-switch designs |
Pinout & Package
ACS120-7ST uses TO-220AB package with isolated tab (electrically connected to COM pin), suitable for direct mounting on heatsinks with insulating washers. Tab serves as thermal path and common reference for neutral-side switching.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| COM | Common reference terminal | Connected to AC neutral or low-side return; electrically tied to metal tab |
| G | Gate input | Negative-triggered control pin; sinks current from MCU GPIO to initiate conduction |
| OUT | Switch output | Connects to load; carries full AC line current during conduction half-cycles |
Key Features
| Feature | Design Value |
|---|---|
| Integrated avalanche clamping | 1100 V typical clamping voltage absorbs inductive turn-off energy without snubber |
| Negative gate triggering | Eliminates need for external gate driver or level shifter when interfacing with 3.3/5 V MCUs |
| No external protection required | Meets IEC 61000-4-5 surge immunity up to 2 kV without varistors or RC networks |
| Shared heatsink compatibility | Electrically isolated tab allows multiple ACS120-7ST devices on same cooling pad without isolation barriers |
| High noise immunity | Static dV/dt >500 V/µs ensures reliable operation in EMI-heavy appliance motor environments |
Applications
| Washing Machine Valve Control | Dishwasher Solenoid Driver |
|---|---|
|
Use Scenario: Precise on/off timing of water inlet valves during fill cycles under variable line voltage and EMI. IC Role / Device Role / Timing Role: AC line switch replacing mechanical relay; provides zero-crossing–free static switching with fast turn-on/turn-off. Use Value: Eliminates contact wear and audible click; withstands 2 kV surges per IEC 61000-4-5 without external protection. |
Use Scenario: Driving detergent dispenser solenoids in compact dishwasher modules with tight thermal constraints. IC Role / Device Role / Timing Role: High-noise-immunity AC switch enabling direct MCU control without optocouplers or drivers. Use Value: Reduces BOM count by 80% vs relay + snubber solution; Rth(j-l) = 2.6 °C/W supports conduction at 2 A RMS on shared heatsink. |
| Refrigerator Defrost Heater | AC Fan Speed Control (On/Off) |
|
Use Scenario: Cycling 2 A resistive defrost heater in freezer compartments with ambient temperatures down to –30 °C. IC Role / Device Role / Timing Role: Solid-state replacement for electromechanical contactor; operates across full Tj range (–30 to +125 °C). Use Value: Enables cold-start reliability; VDRM = ±700 V accommodates 230 VAC + 100% surge margin. |
Use Scenario: Controlling condenser fan motors in air-conditioning units exposed to high dV/dt from nearby compressor switching. IC Role / Device Role / Timing Role: Noise-immune AC switch placed on neutral side to minimize EMI coupling into control circuitry. Use Value: dV/dt immunity >500 V/µs prevents false triggering; integrated clamping avoids voltage overshoot during motor turn-off. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar AC line switching applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ACS120-7SFP | Same die, TO-220FPAB package with insulated tab (no electrical connection to COM) | Required where tab isolation from neutral is mandatory (e.g., double-insulated appliances) | Select when safety certification requires galvanic isolation between heatsink and COM |
| ACS108-7ST | Lower IT(RMS) = 0.8 A; identical VDRM, dV/dt, and clamping architecture | Suitable only for sub-1 A loads like small relays or indicator lamps | Choose for cost-sensitive, low-power applications where 2 A rating is unnecessary |
Compared with ACS120-7SFP, the ACS120-7ST offers lower thermal resistance (2.6 vs 3.5 °C/W) but requires tab isolation if mounted to grounded heatsinks; versus ACS108-7ST, it delivers 2.5× higher RMS current capacity while maintaining identical surge and noise immunity specs.
Availability
ACS120-7ST is available at Aetrix Electronics and suitable for washing machine valve control, dishwasher solenoid driving, and refrigerator defrost heater switching requiring stable component supply across industrial appliance production cycles.
Supply support for ACS120-7ST 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, designing and manufacturing analog, power, and microcontroller solutions for industrial, automotive, and appliance markets.
The ACS™ AC line switch product line targets solid-state replacement of electromechanical relays in white goods, emphasizing snubber-free inductive load switching, IEC 61000-4-5 compliance, and direct MCU interface capability.
FAQ
What is the gate drive polarity requirement for ACS120-7ST?
The ACS120-7ST requires negative gate current-i.e., current must flow *out* of the G pin into the MCU GPIO or driver sink. A series resistor (e.g., 140 Ω with 12 V supply) sets IGT ≤ 10 mA. Positive gate voltage applied to G will not trigger conduction.
Can ACS120-7ST replace a mechanical relay in a 230 VAC, 2 A resistive load?
Yes-ACS120-7ST supports 2 A RMS at Tc = 115 °C with VDRM = ±700 V, providing 100% surge margin above 230 VAC peak (325 V). Its 2 kV IEC 61000-4-5 pulse rating and zero-contact bounce make it a robust relay replacement for resistive heating elements.
Is heatsinking required for continuous 2 A operation?
Yes-Rth(j-l) = 2.6 °C/W requires a heatsink to maintain Tj ≤ 125 °C. At 2 A RMS and Rd = 200 mΩ, conduction loss is ~0.8 W; with ambient at 70 °C, a 25 °C/W heatsink keeps junction temperature at ~105 °C, within spec.
Does ACS120-7ST support zero-crossing switching?
No-ACS120-7ST is a random-phase AC switch. It turns on immediately upon gate trigger and turns off naturally at current zero. For zero-crossing control, external timing circuitry synchronized to AC line is required; the device itself has no built-in zero-cross detection.
ACS120-7ST Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- ASD™
- Package/Case:
- TO-220-3
- Packaging:
- Tube
- Product Status:
- Obsolete
- Triac Type:
- Logic - Sensitive Gate
- Voltage - Off State:
- 700 V
- Current - On State (It (RMS)) (Max):
- 2 A
- Voltage - Gate Trigger (Vgt) (Max):
- 1 V
- Current - Non Rep. Surge 50, 60Hz (Itsm):
- 20A, 11A
- Current - Gate Trigger (Igt) (Max):
- 10 mA
- Current - Hold (Ih) (Max):
- 45 mA
- Configuration:
- Single
- Operating Temperature:
- -30°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220
ACS120-7ST FAQ
1.How can I place an order for ACS120-7ST through Aetrix?
Please submit a Request for Quotation (RFQ) for ACS120-7ST 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 ACS120-7ST reliable?
The price and inventory of ACS120-7ST are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ACS120-7ST is usually 5 days.
3.What payment methods are accepted for ACS120-7ST?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ACS120-7ST transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ACS120-7ST?
ACS120-7ST orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ACS120-7ST 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 ACS120-7ST?
For technical support, including ACS120-7ST datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ACS120-7ST requirements.
6.How does Aetrix verify that ACS120-7ST is sourced from the original manufacturer or authorized distributors?
All ACS120-7ST 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 ACS120-7ST meets industry standards.
7.What is the process for return or replacement of ACS120-7ST?
All ACS120-7ST units undergo pre-shipment inspection (PSI). If there is an issue with ACS120-7ST, 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 ACS120-7ST part is unused and in its original packaging.
Return procedure for ACS120-7ST:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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