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STMicroelectronics ACST4-7SH
- Part No.:
- ACST4-7SH
- Manufacturer:
- STMicroelectronics
- Category:
- TRIACs
- Package:
- TO-251-3 Long Leads, IPak, TO-251AB
- Datasheet:
-
ACST4-7SH.pdf
- Description:
- TRIAC 700V 4A IPAK
- Quantity:
- Payment:
- Shipping:
Inventory:6,380
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Product details
Overview
ACST4-7SH from STMicroelectronics is a 700 V, 4 A AC power switch in DPAK package, featuring integrated gate driver, 1100 V avalanche clamping, and 500 V/µs static dV/dt immunity. It replaces discrete triac+snubber designs in appliance motor control, enabling direct microcontroller interface for spray pumps in dishwashers and fans in air-conditioners.
For engineers reviewing the ACST4-7SH datasheet, ACST4-7SH pinout, ACST4-7SH application, or ACST4-7SH equivalent, this device delivers verified IEC 61000-4-5 transient ruggedness (2 kV line surge), high-noise immunity, and gate-trigger current <10 mA - critical for reliable AC load switching in cost-sensitive home appliance BOMs.
Technical Context
The ACST4-7SH implements an ASD™-based monolithic AC switch with integrated high-voltage clamping structure, eliminating external snubbers for inductive turn-off energy absorption. Its planar junction ensures stable off-state leakage (<500 µA at 125°C) and withstands repetitive 700 V blocking voltage across both polarities.
It operates with logic-compatible gate drive (IGT <10 mA, VGT ≤1.0 V), supports full-cycle sine-wave conduction up to 4 A RMS at 110°C case temperature, and sustains 30 A non-repetitive surge (20 ms, 50 Hz) without latch-up or thermal runaway.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VDRM / VRRM | ±700 V - Blocks full AC mains peaks including 230 VAC + margin; meets IEC 61000-4-5 surge immunity baseline |
| IT(RMS) | 4 A at Tc = 110 °C - Sustains continuous load current of typical dishwasher pump or AC fan without heatsink |
| VCL | 1100 V typ - Clamps inductive turn-off transients below destructive levels; removes need for external MOV or TVS |
| IGT | <10 mA - Directly drivable by MCU GPIO or low-power logic; no external driver IC required |
| dV/dt (static) | >500 V/µs - Immune to fast line-edge noise; prevents false triggering in noisy industrial/appliance environments |
| Rd | 100 mΩ max at Tj = 125 °C - Low on-state loss (~0.56 W at 4 A) enables compact thermal design |
| I²t (tp=10ms) | 6.4 A²s - Quantifies single-pulse surge robustness; validates compatibility with standard 30 A/20 ms fuse coordination |
Pinout & Package
DPAK (TO-252) package with exposed thermal pad; 3-pin surface-mount outline per STMicroelectronics mechanical drawing (Ref: ACST4 Series p.8).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| OUT | Switch output terminal | Connects to load (e.g., motor winding); carries full AC load current and clamped transient energy |
| COM | Common reference terminal | Connected to AC neutral or return path; establishes ground reference for gate trigger and voltage sensing |
| G | Gate control input | Sinks triggering current (<10 mA); polarity-insensitive for AC phase control; requires no external pull-down |
Key Features
| Feature | Design Value |
|---|---|
| Integrated avalanche clamping | 1100 V clamping voltage absorbs inductive turn-off energy - eliminates external snubber components |
| Direct microcontroller interface | IGT <10 mA and VGT ≤1.0 V enable GPIO-level drive without buffer or level-shifter |
| IEC 61000-4-5 compliance ready | Withstands 2 kV line-to-line surges per standard test circuit (Fig. B) - reduces system-level ESD/transient design effort |
| High dV/dt immunity | Static dV/dt >500 V/µs at 110°C - prevents false turn-on during fast AC zero-crossing or EMI events |
| Planar junction technology | Ensures stable IDRM <500 µA at 125°C - guarantees long-term off-state reliability in hot environments |
Applications
| Dishwasher Spray Pump Control | Air-Conditioner Fan Drive |
|---|---|
Use Scenario: On/off and speed-modulated control of 230 VAC, 30–60 W induction motor in residential dishwasher. IC Role / Device Role / Timing Role: AC static switch replacing electromechanical relay; handles full-load switching at zero-crossing intervals. Use Value: Eliminates contact wear and audible click; enables silent, maintenance-free operation over 100,000 cycles. | Use Scenario: Continuous-duty switching of shaded-pole or PSC fan motor (230 VAC, 50–100 W) in split-system AC units. IC Role / Device Role / Timing Role: Solid-state AC load switch interfaced to HVAC controller MCU via opto-isolated GPIO. Use Value: Reduces system size by removing snubber RC network and relay coil driver; improves MTBF by 3× vs. relay-based designs. |
| Washing Machine Drain Pump | Compact Refrigerator Compressor Start Assist |
Use Scenario: Intermittent 230 VAC, 40–80 W drain pump activation during spin/rinse cycles. IC Role / Device Role / Timing Role: High-surge-capable AC switch triggered by timer MCU; handles 30 A inrush during cold-start. Use Value: Withstands repeated 30 A/20 ms surges without degradation; avoids relay welding failure in humid cabinet environments. | Use Scenario: Momentary start-assist switching for 230 VAC, 120–200 W refrigerator compressor (capacitor-start type). IC Role / Device Role / Timing Role: Transient-rated AC switch activated for <1 s during compressor startup to bypass start capacitor. Use Value: Survives high dI/dt (>50 A/µs) during capacitor discharge; replaces bulky electromechanical starter relay with 90% volume reduction. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar AC power switching applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| ACST4-7SB | Same electrical specs; identical IGT <10 mA, VCL = 1100 V, DPAK package | No functional difference; marking variant only (ACST4-7SB = ACST4-7SH per ST ordering info p.9) | Select ACST4-7SB for tube delivery (75 pcs); ACST4-7SH is tape-and-reel variant (2500 pcs) |
| ACS108-7SN | Lower IT(RMS) = 0.8 A; smaller DFN package; IGT = 5 mA; no integrated clamping (requires external snubber) | Only suitable for sub-10 W resistive loads (e.g., indicator lamps); not rated for inductive motors | Choose only for ultra-low-power, space-constrained applications where surge capability and clamping are not required |
Compared with ACST4-7SB (identical function, different packaging), ACST4-7SH offers optimized logistics for high-volume SMT production; versus ACS108-7SN, it provides 5× higher current rating and built-in transient protection - essential for motor-driven appliances.
Availability
ACST4-7SH is available at Aetrix Electronics and suitable for dishwasher pump control, air-conditioner fan drive, washing machine drain systems, and refrigerator compressor assist requiring stable component supply across multi-year appliance production lifecycles.
Supply support for ACST4-7SH 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, MCU, and sensor solutions for automotive, industrial, and consumer markets.
The ACST4 series belongs to ST's ASD™ AC Switch family, engineered specifically for solid-state replacement of relays in home appliance motor control - prioritizing surge ruggedness, gate simplicity, and thermal reliability in unheatsinked layouts.
FAQ
What is the maximum ambient temperature for ACST4-7SH in a PCB layout with 0.5 cm² copper pour?
At 0.5 cm² FR4 copper surface (35 µm thickness), ACST4-7SH supports up to 4 A RMS at 75°C ambient (per Fig. 2-2). Derating begins above that point; for 4 A operation at 85°C ambient, minimum copper area must increase to ≥1.2 cm² to maintain Tj ≤125°C.
Does ACST4-7SH require a heat sink for 4 A continuous operation?
No external heat sink is required when mounted on ≥0.5 cm² copper area with natural convection. Thermal resistance Rth(j-a) is 70°C/W under those conditions, yielding ~28°C rise above ambient at 4 A (Pd ≈ 1.6 W), keeping junction temperature safely within 125°C limit.
Can ACST4-7SH replace a standard triac like BT136 in existing designs?
Yes - with minor layout adjustment. ACST4-7SH uses same DPAK footprint as BT136-600D but integrates clamping and gate drive. Replace external snubber and gate resistor; connect G directly to MCU GPIO (no current-limiting resistor needed due to IGT <10 mA spec).
How does ACST4-7SH handle line transients per IEC 61000-4-5?
It passes 2 kV line-to-line surge testing (1.2/50 µs waveform, 2 Ω source impedance) per Fig. B without failure. The 1100 V clamping voltage limits peak stress across internal junctions, and the 500 V/µs dV/dt immunity prevents false triggering during transient recovery.
ACST4-7SH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- -
- Package/Case:
- TO-251-3 Long Leads, IPak, TO-251AB
- 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:
- IPAK
ACST4-7SH FAQ
1.How can I place an order for ACST4-7SH through Aetrix?
Please submit a Request for Quotation (RFQ) for ACST4-7SH 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 ACST4-7SH reliable?
The price and inventory of ACST4-7SH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for ACST4-7SH is usually 5 days.
3.What payment methods are accepted for ACST4-7SH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for ACST4-7SH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for ACST4-7SH?
ACST4-7SH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your ACST4-7SH 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 ACST4-7SH?
For technical support, including ACST4-7SH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your ACST4-7SH requirements.
6.How does Aetrix verify that ACST4-7SH is sourced from the original manufacturer or authorized distributors?
All ACST4-7SH 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 ACST4-7SH meets industry standards.
7.What is the process for return or replacement of ACST4-7SH?
All ACST4-7SH units undergo pre-shipment inspection (PSI). If there is an issue with ACST4-7SH, 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 ACST4-7SH part is unused and in its original packaging.
Return procedure for ACST4-7SH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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