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Home > Products > Discrete Semiconductor Products > Thyristors > TRIACs

STMicroelectronics TXDV812RG

Name: TXDV812RG
Brand: STMicroelectronics
SKU: TXDV812RG
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: TXDV812RG

Manufacturer:: STMicroelectronics

Category:: TRIACs

Package:: TO-220-3

Datasheet:: TXDV812RG.pdf

Description:: TRIAC ALTERNISTOR 800V 12A TO220

Quantity:: RFQ Add To RFQ list

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Inventory:4,190

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Product details

Overview

TXDV812RG from STMicroelectronics is a high-voltage insulated triac with 12 A RMS on-state current, 800 V repetitive peak off-state voltage (VDRM/VRRM), and 100 mA gate trigger current (IGT), designed for robust AC power control in three-phase industrial systems. It features 42.5 A/ms critical rate of rise of on-state current (dI/dt)c, 2 kV/µs noise immunity, and UL-recognized 2500 V_RMS insulation between terminals and case.

For engineers reviewing the TXDV812RG datasheet, TXDV812RG pinout, TXDV812RG application, or TXDV812RG equivalent, key selection criteria include commutation capability under inductive load stress, thermal resistance (R_th(j-c) = 1.9 °C/W at 360° conduction), surge rating (125 A @ 8.3 ms), gate drive compatibility (100 mA IGT), and TO-220AB insulated package mounting requirements.

Technical Context

This alternistor-based triac uses high-performance silicon technology to support reliable turn-on and commutation in phase-controlled AC circuits with inductive loads. Its 42.5 A/ms (dI/dt)_c and 2 kV/µs (dV/dt)_c ratings enable stable operation in motor starters and heating controllers where rapid voltage transients and high di/dt are common.

The device operates across -40 °C to +125 °C junction temperature range and delivers 1.95 V maximum on-state voltage (V_TM) at 17 A, with dynamic resistance ≤40 mΩ and threshold voltage ≤1.21 V - enabling low conduction loss and predictable gate triggering even at elevated temperatures.

Key Specifications

Parameter	Value and Actual Design Meaning
IT(RMS)	12 A - supports continuous load current up to 12 A RMS at Tc = 90 °C without derating
VDRM / VRRM	800 V - blocks 800 V peak AC voltage in both directions, suitable for 400 V three-phase line applications
IGT	100 mA - gate trigger current requirement compatible with standard microcontroller GPIO or optocoupler drivers
(dI/dt)c	42.5 A/ms - sustains high-rate current rise during turn-on, preventing false commutation in inductive motor loads
VINS(RMS)	2500 V - provides reinforced isolation between main terminals and heatsink-mounted case per UL E81734
Rth(j-c) AC	1.9 °C/W - enables efficient heat transfer to heatsink under full-conduction 50 Hz operation
VTM @ 17 A	1.95 V - low conduction drop reduces power dissipation and thermal stress in high-current switching

Pinout & Package

TXDV812RG is housed in a TO-220AB insulated package with creepage/clearance enhanced for high-voltage safety. The case is electrically isolated from all terminals (A1, A2, G), rated for 2500 V_RMS insulation.

Pin/Terminal	Circuit Role	Design Meaning
A2	Main terminal 2	AC line or phase input connection; carries full load current in either direction when triggered
A1	Main terminal 1	Load return path; forms bidirectional conduction path with A2 through silicon structure
G	Gate	Control input that initiates conduction when ≥100 mA pulse applied relative to A1

Key Features

Feature	Design Value
High commutation robustness	42.5 A/ms (dI/dt)_c ensures reliable turn-off in inductive motor and transformer loads
Enhanced noise immunity	2 kV/µs (dV/dt)_c prevents false triggering from EMI in industrial environments
UL-recognized insulation	2500 V_RMS isolation allows direct mounting to grounded heatsinks without additional insulation
High surge capability	125 A non-repetitive surge current (8.3 ms) supports motor startup and fault transient handling

Applications

Heating System Control

Motor Starter

Use Scenario: Phase-angle controlled resistive heating in industrial ovens and furnaces using three-phase 400 V supply.

IC Role / Device Role / Timing Role: Bidirectional AC switch controlling power delivery to heater elements via zero-crossing or phase-shifted gating.

Use Value: 800 V blocking voltage and 12 A RMS rating match standard three-phase heating load profiles while maintaining safe margin.

Use Scenario: Soft-start circuitry for three-phase induction motors in HVAC blowers and pumps.

IC Role / Device Role / Timing Role: High-current AC switch enabling gradual voltage ramp-up to limit inrush current during motor energization.

Use Value: 42.5 A/ms (dI/dt)_c and 125 A surge rating prevent commutation failure during high-inductance motor turn-on transients.

Induction Motor Speed Control

Industrial Transformer Tap Switching

Use Scenario: Fan speed regulation in commercial air-handling units using phase-controlled AC voltage reduction.

IC Role / Device Role / Timing Role: Alternistor triac delivering variable RMS voltage to single-phase or three-phase fan windings.

Use Value: Low V_TM (1.95 V) and 40 mΩ dynamic resistance minimize conduction losses at partial-load operating points.

Use Scenario: Automatic tap selection in industrial power distribution transformers under load.

IC Role / Device Role / Timing Role: Isolated high-voltage switch enabling make-before-break or break-before-make transitions between taps.

Use Value: 2500 V_RMS insulation and 800 V blocking rating ensure galvanic isolation and safe operation across transformer secondary windings.

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-voltage triac power control applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
BTB12-800CW	Same 12 A/800 V rating but non-insulated TO-220 package; R_th(j-c) = 1.5 °C/W (lower thermal resistance)	Requires external insulating washer for heatsink mounting; unsuitable where reinforced isolation is mandated	Select when thermal performance is prioritized over isolation and board space permits added insulation layer
Q6012LH5	12 A/600 V rating; lower blocking voltage; higher IGT (50 mA typical); no UL insulation rating	Limited to 230 V single-phase or low-voltage three-phase systems; not certified for direct heatsink mounting	Select only for cost-sensitive 230 V applications where isolation compliance is not required

Compared with BTB12-800CW and Q6012LH5, TXDV812RG uniquely combines UL-recognized 2500 V_RMS insulation, 800 V blocking, and 42.5 A/ms commutation - making it the only option qualified for safety-critical, high-di/dt three-phase industrial controls requiring direct heatsink mounting.

Availability

TXDV812RG is available at Aetrix Electronics and suitable for industrial heating systems, motor starters, induction motor speed control, and transformer tap switching requiring stable component supply and long-term lifecycle support.

Supply support for TXDV812RG 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, designing and manufacturing analog, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The TXDVxx12 series belongs to ST's high-reliability power discrete portfolio, engineered specifically for ruggedized AC power control in three-phase industrial equipment where commutation robustness and reinforced insulation are mandatory.

FAQ

What is the maximum allowable case temperature for continuous 12 A operation?

At 12 A RMS and 180° conduction angle, the maximum case temperature is 90 °C per Table 2. Exceeding this requires derating - Figure 3 shows linear derating to 0 A at 125 °C case temperature. Thermal design must maintain R_th(j-c) ≤ 1.9 °C/W and ambient conditions within specification limits.

Can TXDV812RG replace TXDV1212RG in a design?

No - TXDV1212RG has 1200 V blocking voltage versus 800 V for TXDV812RG. Substitution is unsafe in 690 V three-phase or high-voltage 400 V grid applications where 1200 V rating is required for margin. Electrical stress and reliability will be compromised if used beyond its 800 V VDRM limit.

Is a heatsink mandatory for TXDV812RG operation at full 12 A rating?

Yes - the R_th(j-c) of 1.9 °C/W assumes direct conduction cooling via a properly torqued (0.4–0.6 N·m) heatsink. Without heatsinking, junction temperature would exceed 125 °C almost immediately at 12 A due to ~23 W conduction loss (1.95 V × 12 A), violating absolute maximum ratings.

Does TXDV812RG support quadrant III triggering?

Yes - datasheet Table 3 specifies IGT, VGT, and VGD values for quadrants I, II, and III. Gate triggering works with A2 negative relative to A1 (quadrant III), enabling full-wave AC control without external polarity reversal circuitry - essential for compact three-phase phase-control designs.

TXDV812RG Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Obsolete

Triac Type:: Alternistor - Snubberless

Voltage - Off State:: 800 V

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

Voltage - Gate Trigger (Vgt) (Max):: 1.5 V

Current - Non Rep. Surge 50, 60Hz (Itsm):: 120A, 125A

Current - Gate Trigger (Igt) (Max):: 100 mA

Current - Hold (Ih) (Max):: 100 mA

Configuration:: Single

Operating Temperature:: -40°C ~ 125°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220

TXDV812RG FAQ

1.How can I place an order for TXDV812RG through Aetrix?

Please submit a Request for Quotation (RFQ) for TXDV812RG 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 TXDV812RG reliable?

The price and inventory of TXDV812RG are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TXDV812RG is usually 5 days.

3.What payment methods are accepted for TXDV812RG?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TXDV812RG transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for TXDV812RG?

TXDV812RG orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your TXDV812RG 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 TXDV812RG?

For technical support, including TXDV812RG datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TXDV812RG requirements.

6.How does Aetrix verify that TXDV812RG is sourced from the original manufacturer or authorized distributors?

All TXDV812RG 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 TXDV812RG meets industry standards.

7.What is the process for return or replacement of TXDV812RG?

All TXDV812RG units undergo pre-shipment inspection (PSI). If there is an issue with TXDV812RG, 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 TXDV812RG part is unused and in its original packaging.

Return procedure for TXDV812RG:

1.Submit a request within 90 days.

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

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