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Home > Products > Discrete Semiconductor Products > Thyristors > TRIACs

STMicroelectronics T1235-800G-TR

Name: T1235-800G-TR
Brand: STMicroelectronics
SKU: T1235-800G-TR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: T1235-800G-TR

Manufacturer:: STMicroelectronics

Category:: TRIACs

Package:: TO-263-3, D2PAK (2 Leads + Tab), TO-263AB

Datasheet:: T1235-800G-TR.pdf

Description:: TRIAC ALTERNISTOR 800V 12A D2PAK

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Product details

Overview

T1235-800G-TR from STMicroelectronics is a Snubberless™ 3-quadrant triac in D²PAK package, rated for 12 A RMS on-state current and 800 V off-state blocking voltage, with 35 mA gate trigger current (IGT), designed for reliable AC mains switching in inductive load applications such as motor speed control and heating regulation.

For engineers reviewing the T1235-800G-TR datasheet, T1235-800G-TR pinout, T1235-800G-TR application, or T1235-800G-TR equivalent, key selection criteria include commutation robustness (dV/dt = 500 V/µs, (dl/dt)c ≥ 6.5 A/ms), insulated thermal performance (Rth(j-c) = 1.4 °C/W), and UL1557-certified isolation (2500 VRMS tab rating).

Technical Context

This triac operates in 3-quadrant mode (I, II, III), enabling high-noise immunity and stable triggering without external snubbers. Its internal ceramic insulation ensures 2500 VRMS isolation between the tab and die, meeting UL1557 (file E81734) for safety-critical AC line applications.

The device delivers high commutation capability: dV/dt = 500 V/µs at Tj = 125 °C with gate open, and critical rate of decrease of main current (dl/dt)c ≥ 6.5 A/ms under specified dV/dt conditions - essential for driving inductive loads like universal motors and solenoids without false turn-off.

Key Specifications

Parameter	Value and Actual Design Meaning
IT(RMS)	12 A - supports continuous AC load currents up to 12 A RMS in full-sine wave operation.
VDRM / VRRM	800 V - blocks peak line voltages up to 800 V, suitable for 400–480 VAC industrial systems.
IGT (Snubberless)	35 mA - low gate drive requirement compatible with standard microcontroller GPIO or optocoupler outputs.
dV/dt (min)	500 V/µs - withstands rapid voltage transients without false triggering, eliminating need for snubber networks.
Rth(j-c)	1.4 °C/W - enables efficient heat transfer to heatsink; allows 12 A operation at Tc ≤ 105 °C.
Isolation Voltage	2500 VRMS - certified reinforced insulation per UL1557, enabling safe mounting on grounded metal chassis.
VTM (max)	1.55 V - low conduction loss at ITM = 17 A, minimizing power dissipation and thermal stress.

Pinout & Package

D²PAK (TO-263) surface-mount package with insulated tab, RoHS-compliant, halogen-free molding compound (UL V0), and lead-free terminations. Tab is electrically isolated and rated for 2500 VRMS.

Pin/Terminal	Circuit Role	Design Meaning
A1 (MT1)	Main Terminal 1	Reference terminal for gate trigger; connected to load return or neutral side in AC switching.
A2 (MT2)	Main Terminal 2	High-side AC line connection; carries full load current and defines polarity reference for quadrants.
G	Gate	Trigger input; requires ≥35 mA pulse to initiate conduction in quadrants I, II, III only.
Tab	Isolated Heat Sink Interface	Electrically isolated (2500 VRMS) metal pad for mechanical mounting and thermal conduction; no electrical connection to die.

Key Features

Feature	Design Value
Snubberless™ Operation	Enables direct drive of inductive loads (e.g., motors, transformers) without external RC snubbers, reducing BOM count and board space.
UL1557 Certification	File E81734 confirms reinforced insulation integrity - eliminates need for additional creepage/clearance design effort in safety-critical AC mains interfaces.
3-Quadrant Triggering	Blocks quadrant IV triggering, improving noise immunity and preventing unintended turn-on during negative half-cycle transients.
Low Rth(j-c)	1.4 °C/W thermal resistance allows compact thermal design: 12 A RMS sustained with modest heatsinking at Tc ≤ 105 °C.
ECOPACK2® Compliance	Fully RoHS-compliant, halogen-free, lead-free package meeting stringent environmental manufacturing requirements.

Applications

Motor Speed Control

Heating Regulation

Use Scenario: Variable-speed control of universal motors in power tools and kitchen appliances using phase-angle firing.

IC Role / Device Role / Timing Role: Main AC power switch triggered synchronously with zero-crossing detection to modulate RMS voltage delivered to motor winding.

Use Value: Eliminates snubber components while maintaining reliable commutation across full speed range, even under high inductance and load transients.

Use Scenario: Proportional power delivery to resistive heating elements in industrial ovens and HVAC duct heaters.

IC Role / Device Role / Timing Role: High-reliability ON/OFF or phase-control switch interfacing with microcontroller-based PID temperature controllers.

Use Value: 800 V blocking voltage accommodates 400 VAC three-phase line spikes; 2500 VRMS isolation ensures operator safety in Class I equipment.

Static Relay Replacement

Light Dimmer for Inductive Lamps

Use Scenario: Solid-state replacement for electromechanical relays in PLC output modules handling 240–480 VAC loads.

IC Role / Device Role / Timing Role: Fail-safe AC switching element with galvanic isolation between control logic and power circuitry.

Use Value: 12 A RMS rating supports typical industrial load currents; UL-certified isolation meets IEC 61800-5-1 functional safety requirements.

Use Scenario: Leading-edge dimming of magnetic low-voltage transformers and electronic transformers powering halogen lamps.

IC Role / Device Role / Timing Role: Snubberless triac providing clean, jitter-free phase-cutting without voltage overshoot or false re-triggering.

Use Value: 500 V/µs dV/dt rating prevents misfiring during transformer saturation events; 35 mA IGT ensures compatibility with standard TRIAC driver ICs.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
BTA12-800CW	TO-220AB insulated package; identical 12 A / 800 V / 35 mA specs; Rth(j-c) = 2.3 °C/W vs. 1.4 °C/W.	Through-hole mounting; requires larger PCB footprint and manual assembly; better suited for prototyping or low-volume repair.	Select when through-hole assembly or higher creepage distance is required; avoid if thermal budget is tight or SMT automation is used.
T1235-600G-TR	Same D²PAK package and 35 mA IGT, but 600 V VDRM instead of 800 V; otherwise identical thermal and commutation specs.	Limited to 277 VAC single-phase or 480 VAC line-to-line with margin; unsuitable for 400 VAC industrial mains with surge tolerance requirements.	Select only for cost-sensitive 230/277 VAC applications where 800 V derating is unnecessary; verify system overvoltage protection.

Compared with BTA12-800CW and T1235-600G-TR, the T1235-800G-TR uniquely combines surface-mount scalability, superior thermal performance (1.4 °C/W), and 800 V robustness - making it optimal for high-density, thermally constrained, and industrial-grade AC power control designs.

Availability

T1235-800G-TR is available at Aetrix Electronics and suitable for motor speed control, heating regulation, static relay replacement, and light dimmer applications requiring stable component supply, long-term lifecycle support, and UL-certified isolation.

Supply support for T1235-800G-TR 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, delivering innovative analog, power, and microcontroller solutions for industrial, automotive, and consumer markets.

The T12xx series belongs to ST's high-reliability Snubberless™ triac product line, engineered specifically for robust, snubber-free AC mains switching in safety-critical and thermally demanding industrial environments.

FAQ

What is the maximum junction temperature and thermal resistance of T1235-800G-TR?

The device has an operating junction temperature range of –40 °C to +125 °C. Its maximum junction-to-case thermal resistance (Rth(j-c)) is 1.4 °C/W for the D²PAK package, measured under AC conditions. This value enables 12 A RMS operation when case temperature is maintained at or below 105 °C using appropriate heatsinking.

Does T1235-800G-TR require a snubber circuit when driving inductive loads?

No - the T1235-800G-TR is a Snubberless™ triac with guaranteed dV/dt = 500 V/µs and (dl/dt)c ≥ 6.5 A/ms, allowing direct connection to inductive loads like motors and transformers without external RC snubbers. This is validated per DS2115 Rev 12 test conditions at Tj = 125 °C.

How is the insulated tab rated, and what safety certification applies?

The D²PAK tab is electrically isolated and rated for 2500 VRMS working voltage. It is UL1557 certified (file E81734), confirming reinforced insulation suitable for use in Class I equipment where user-accessible parts must be protected against hazardous voltage under single-fault conditions.

What gate drive circuitry is recommended for reliable triggering?

A minimum 35 mA DC or pulsed gate current (IGT) is required at VD = 12 V and RL = 30 Ω. Standard optocouplers (e.g., MOC3041, IL420) or dedicated triac drivers (e.g., STMicroelectronics TS6200) provide sufficient current. Gate resistor should limit peak current to ≤4 A (per IGM spec) and ensure rise time <100 ns for optimal commutation performance.

T1235-800G-TR Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: Snubberless™

Package/Case:: TO-263-3, D2PAK (2 Leads + Tab), TO-263AB

Packaging:: Tape & Reel (TR)

Product Status:: Active

Triac Type:: Alternistor - Snubberless

Voltage - Off State:: 800 V

Current - On State (It (RMS)) (Max):: 12 A

Voltage - Gate Trigger (Vgt) (Max):: 1.3 V

Current - Non Rep. Surge 50, 60Hz (Itsm):: 120A, 126A

Current - Gate Trigger (Igt) (Max):: 35 mA

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

Configuration:: Single

Operating Temperature:: -40°C ~ 125°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: D2PAK

T1235-800G-TR FAQ

1.How can I place an order for T1235-800G-TR through Aetrix?

Please submit a Request for Quotation (RFQ) for T1235-800G-TR 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 T1235-800G-TR reliable?

The price and inventory of T1235-800G-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for T1235-800G-TR is usually 5 days.

3.What payment methods are accepted for T1235-800G-TR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for T1235-800G-TR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for T1235-800G-TR?

T1235-800G-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your T1235-800G-TR 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 T1235-800G-TR?

For technical support, including T1235-800G-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your T1235-800G-TR requirements.

6.How does Aetrix verify that T1235-800G-TR is sourced from the original manufacturer or authorized distributors?

All T1235-800G-TR 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 T1235-800G-TR meets industry standards.

7.What is the process for return or replacement of T1235-800G-TR?

All T1235-800G-TR units undergo pre-shipment inspection (PSI). If there is an issue with T1235-800G-TR, 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 T1235-800G-TR part is unused and in its original packaging.

Return procedure for T1235-800G-TR:

1.Submit a request within 90 days.

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

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