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STMicroelectronics T850-8G-TR
- Part No.:
- T850-8G-TR
- Manufacturer:
- STMicroelectronics
- Category:
- TRIACs
- Package:
- TO-263-3, D2PAK (2 Leads + Tab), TO-263AB
- Datasheet:
-
T850-8G-TR.pdf
- Description:
- TRIAC ALTERNISTOR 800V 8A D2PAK
- Quantity:
- Payment:
- Shipping:
Inventory:6,801
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Product details
Overview
T850-8G-TR from STMicroelectronics is a snubberless 8 A, 800 V RMS triac in D²PAK (TO-263) surface-mount package, designed for phase-controlled AC switching in inductive loads. It features 50 mA maximum gate trigger current (IGT), 400 V/µs dV/dt immunity at 125 °C, and 50 mΩ dynamic on-state resistance - enabling direct microcontroller interfacing and robust operation in motor speed controllers and heating regulation circuits.
For engineers reviewing the T850-8G-TR datasheet, T850-8G-TR pinout, T850-8G-TR application, or T850-8G-TR equivalent, key selection criteria include snubberless commutation performance, logic-level gate sensitivity for low-power drive, thermal resistance (Rth(j-c) = 1.6 °C/W), and D²PAK mounting compatibility with high-current PCB layouts.
Technical Context
This triac operates in three quadrants (I, II, III) with snubberless commutation capability, supporting reliable turn-off under inductive load conditions without external snubber networks. Its gate threshold voltage (VGT ≤ 1.2 V) and low IGT (max 50 mA) allow direct drive from 3.3 V or 5 V microcontrollers without buffer stages.
The device delivers 8 A RMS on-state current at case temperature TC = 110 °C, supported by a junction-to-case thermal resistance of 1.6 °C/W. Critical design parameters include 4.5 A/ms minimum commutating di/dt at 125 °C and 1000 V/µs dV/dt immunity for high-noise industrial environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| IT(RMS) | 8 A RMS - supports continuous AC load current up to 8 A at TC = 110 °C in D²PAK package |
| VDRM / VRRM | 800 V - peak off-state blocking voltage for 230 VAC + margin applications |
| IGT (max) | 50 mA - gate trigger current compatible with MCU GPIO without external driver |
| dV/dt (min) | 400 V/µs @ Tj = 125 °C - enables stable operation on inductive loads without snubber |
| Rth(j-c) | 1.6 °C/W - allows efficient heat transfer to heatsink or copper pour in power PCB designs |
| VTM | 1.55 V @ ITM = 11 A - low conduction loss reduces thermal stress in high-duty-cycle dimmers |
| (dl/dt)c | 4.5 A/ms @ (dV/dt)c = 0.1 V/µs - ensures reliable commutation during zero-crossing switching |
Pinout & Package
D²PAK (TO-263) surface-mount package with isolated tab (non-insulated version); thermal pad on underside requires soldered copper area ≥ 10 cm² for rated current derating per Figure 3.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A1 | Main Terminal 1 | Reference terminal for gate triggering; connects to load return or neutral side |
| A2 | Main Terminal 2 | High-side AC line connection; carries full load current and withstands 800 V peak |
| G | Gate | Low-power control input; triggers conduction when referenced to A1 with ≥50 mA pulse |
Key Features
| Feature | Design Value |
|---|---|
| Snubberless commutation | Enables elimination of RC snubber networks in motor and transformer loads, reducing BOM count and board space |
| Logic-level gate sensitivity | IGT ≤ 50 mA and VGT ≤ 1.2 V permit direct interface with 3.3 V/5 V microcontrollers and logic buffers |
| High dV/dt immunity | 400 V/µs minimum at 125 °C prevents false triggering in noisy industrial AC environments |
| D²PAK thermal performance | Rth(j-c) = 1.6 °C/W supports 8 A RMS with minimal heatsinking on 2 oz copper PCBs |
| Three-quadrant operation | Eliminates unnecessary gate triggering in QIV, improving EMI and reducing gate drive complexity |
Applications
| Motor Speed Control | Light Dimming |
|---|---|
Use Scenario: Variable-speed control of single-phase induction motors in HVAC blowers and power tools. IC Role / Device Role / Timing Role: Phase-angle controlled AC switch regulating RMS voltage delivered to motor windings. Use Value: Snubberless operation avoids capacitor failure in high-vibration environments; 800 V rating accommodates 230 VAC mains with surge margin. |
Use Scenario: Leading-edge dimming of incandescent and halogen lamps in residential and commercial lighting. IC Role / Device Role / Timing Role: Bidirectional AC switch triggered at programmable phase angle to adjust lamp brightness. Use Value: 50 mA IGT enables direct PWM output drive from MCU timers; low VTM minimizes self-heating at high duty cycles. |
| Heating Regulation | Static Relay Replacement |
Use Scenario: Proportional power delivery to resistive heating elements in industrial ovens and soldering stations. IC Role / Device Role / Timing Role: Solid-state ON/OFF or phase-control switch replacing electromechanical contactors. Use Value: 8 A RMS rating supports 1.8 kW loads at 230 VAC; D²PAK package allows automated SMT assembly and high-reliability operation. |
Use Scenario: Zero-crossing or phase-controlled replacement of mechanical relays in PLC I/O modules and energy meters. IC Role / Device Role / Timing Role: Isolation-free AC power switch with galvanic separation provided by system-level optocoupler. Use Value: 4.5 A/ms commutating di/dt ensures clean turn-off under inductive relay coil back-EMF; tape-and-reel packaging (TR) supports high-volume pick-and-place. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar triac-based AC switching applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BTA08-800BW | TO-220AB insulated package; Rth(j-c) = 2.5 °C/W; same 8 A/800 V/50 mA specs | Requires mechanical mounting and isolation hardware; better suited for through-hole prototyping or low-volume assemblies | Select when board space permits screw-mount heatsinks and UL-rated insulation is mandatory |
| T835-8G-TR | Same D²PAK package but 35 mA IGT; lower gate sensitivity and reduced dV/dt (1000 V/µs → 400 V/µs) | Less immune to noise-induced false triggering; suitable only for resistive or lightly inductive loads | Select when gate drive strength is limited and load inductance is low (e.g., heater-only systems) |
Compared with BTA08-800BW, T850-8G-TR offers superior thermal performance and SMT scalability; compared with T835-8G-TR, it provides higher gate drive margin and stronger noise immunity for demanding motor control applications.
Availability
T850-8G-TR is available at Aetrix Electronics and suitable for motor speed control, light dimming, heating regulation, and static relay replacement requiring stable component supply across industrial production cycles.
Supply support for T850-8G-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, specializing in power discrete devices, microcontrollers, and analog ICs for industrial, automotive, and consumer markets.
T850-8G-TR belongs to ST's T8 series of snubberless triacs, engineered specifically for high-reliability AC power control in inductive-load applications where traditional snubbers compromise size, cost, and reliability.
FAQ
What is the maximum junction temperature for continuous operation?
The T850-8G-TR has an operating junction temperature range of –40 °C to +125 °C. Continuous operation at Tj = 125 °C is permitted when case temperature is maintained at TC = 110 °C per Table 1, with appropriate PCB copper area and airflow per Figure 3 and Figure 12.
Does this triac require a heatsink in standard PCB layouts?
A heatsink is not required if the D²PAK thermal pad is soldered to ≥10 cm² of 2 oz copper on FR4 PCB (per Figure 3). For sustained 8 A RMS loads above ambient >50 °C, a low-profile aluminum heatsink bolted to the tab improves thermal margin and extends lifetime.
Can T850-8G-TR replace a BTA08-800B in existing designs?
No - BTA08-800B uses TO-220AB insulated package with different pinout, mounting, and thermal path. While electrical specs align, mechanical redesign is required for D²PAK footprint, solder paste profile, and thermal pad layout. Use BTA08-800BW only for drop-in replacement in through-hole designs.
Is the gate trigger polarity sensitive?
Yes - T850-8G-TR operates in quadrants I, II, and III only. Gate must be positive relative to A1 for QI triggering and negative relative to A1 for QII/QIII. Quadrant IV triggering is disabled, reducing false turn-on risk from noise on the gate line.
T850-8G-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):
- 8 A
- Voltage - Gate Trigger (Vgt) (Max):
- 1.2 V
- Current - Non Rep. Surge 50, 60Hz (Itsm):
- 80A, 84A
- Current - Gate Trigger (Igt) (Max):
- 50 mA
- Current - Hold (Ih) (Max):
- 75 mA
- Configuration:
- Single
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- D2PAK
T850-8G-TR FAQ
1.How can I place an order for T850-8G-TR through Aetrix?
Please submit a Request for Quotation (RFQ) for T850-8G-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 T850-8G-TR reliable?
The price and inventory of T850-8G-TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for T850-8G-TR is usually 5 days.
3.What payment methods are accepted for T850-8G-TR?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for T850-8G-TR transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for T850-8G-TR?
T850-8G-TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your T850-8G-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 T850-8G-TR?
For technical support, including T850-8G-TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your T850-8G-TR requirements.
6.How does Aetrix verify that T850-8G-TR is sourced from the original manufacturer or authorized distributors?
All T850-8G-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 T850-8G-TR meets industry standards.
7.What is the process for return or replacement of T850-8G-TR?
All T850-8G-TR units undergo pre-shipment inspection (PSI). If there is an issue with T850-8G-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 T850-8G-TR part is unused and in its original packaging.
Return procedure for T850-8G-TR:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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