ACST1235-8FPA STMicroelectronics Integrated Circuit (Transistor Outline, Vertical) In Stock
ACST1235-8FPA is an overvoltage-protected AC switch by STMicroelectronics rated for 12 A RMS and 800 V repetitive peak voltage. Key specs: isolated TO-220F vertical package, integrated overvoltage protection, suitable for 230 VAC mains loads. In stock with worldwide shipping.
- Manufacturer
- STMicroelectronics
- Package
- Transistor Outline, Vertical
- Pin Count
- 3
- Lifecycle
- ACTIVE
- Datasheet
- ACST1235-8FPA Datasheet PDF
- Category
- Integrated Circuit
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
What are the key features of ACST1235-8FPA?
- 12 A RMS continuous current rating handles resistive and inductive mains loads up to 2.8 kW at 230 VAC without derating
- 800 V repetitive peak blocking voltage with integrated overvoltage protection reduces need for external snubber networks on inductive AC loads
- TO-220F isolated vertical package provides insulation between the drain/anode and heatsink tab, simplifying thermal management without mica washers
- AC switch topology enables direct phase-control or zero-cross switching of 50 Hz/60 Hz mains, replacing bulky relay modules in home-automation and industrial designs
What is ACST1235-8FPA used for?
ACST1235-8FPA is designed for residential and light-commercial appliance control, including electric heating elements, motor soft-starters, and lighting dimmers operating on 230 VAC or 120 VAC mains. Its integrated overvoltage protection makes it well suited for switching inductive loads such as fan motors and solenoid valves where back-EMF spikes can otherwise destroy standard triacs. Industrial panel builders also use it to replace mechanical relays in solid-state relay (SSR) modules rated up to 12 A, improving switching speed and eliminating contact wear.
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
Where can I find the ACST1235-8FPA datasheet?
ACST1235-8FPA Datasheet DownloadOfficial datasheet from STMicroelectronics
What are equivalent replacements for ACST1235-8FPA?
Compatible alternatives and drop-in replacements for ACST1235-8FPA:
Frequently Asked Questions
What is the maximum continuous current and blocking voltage of ACST1235-8FPA for a 230 VAC heating element application?
ACST1235-8FPA is rated for 12 A RMS continuous load current and 800 V repetitive peak off-state voltage (VDRM). At 230 VAC (325 V peak), the 800 V rating provides roughly 2.5× safety margin above the mains peak, accommodating line transients. A 12 A rating allows control of resistive heating elements up to approximately 2.76 kW at 230 VAC without derating, covering most domestic electric heater and towel-rail applications.
How does the integrated overvoltage protection in ACST1235-8FPA simplify inductive load switching compared to a standard triac?
When switching inductive loads like motors and solenoids, turn-off produces a voltage spike that can exceed the device's blocking voltage and cause false triggering or permanent damage in standard triacs. ACST1235-8FPA integrates an overvoltage protection clamp, reducing or eliminating the need for external RC snubber networks — typically a 47 Ω to 100 Ω resistor in series with a 10 nF to 100 nF capacitor — which lowers BOM cost and simplifies PCB layout for solid-state relay designs.
What advantage does the TO-220F isolated package of ACST1235-8FPA offer for mounting in a metal enclosure?
The TO-220F vertical package includes an insulated mounting tab, providing typically 2500 V isolation between the active device terminals and the metal mounting surface. This eliminates the need for insulating mica washers or TO-220 isolation kits when fastening to a grounded metal chassis or heatsink, saving assembly time and reducing the risk of insulation failure from improperly installed washers in production environments.
When designing a solid-state relay module with ACST1235-8FPA to replace a 10 A mechanical relay, what key electrical parameters should be verified?
Key parameters to verify include: maximum load current (12 A RMS vs. relay's 10 A rating — ACST1235-8FPA exceeds it), off-state blocking voltage (800 V covering 230 VAC + transients), on-state voltage drop (typically 1.5 V at 12 A, producing up to 18 W dissipation that requires a heatsink), and gate trigger current (typically 35 mA to 50 mA from an optocoupler or microcontroller with a MOSFET driver). Confirming di/dt and dv/dt ratings against the load's transient profile completes the evaluation.
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Why Buy from FindMyChip
About STMicroelectronics
STMicroelectronics is a global semiconductor leader serving customers across the spectrum of electronics applications. ST's products are found in a wide range of applications including automotive, industrial, personal electronics, and communications.
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