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Home > Products > Discrete Semiconductor Products > Thyristors > TRIACs

STMicroelectronics T1635T-8I

Name: T1635T-8I
Brand: STMicroelectronics
SKU: T1635T-8I
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: T1635T-8I

Manufacturer:: STMicroelectronics

Category:: TRIACs

Package:: TO-220-3

Datasheet:: T1635T-8I.pdf

Description:: TRIAC ALTERNSTR 800V 16A TO220AB

Quantity:: RFQ Add To RFQ list

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Inventory:1,662

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Product details

Overview

T1635T-8I from STMicroelectronics is a snubberless, three-quadrant 16 A triac in a TO-220AB insulated package, rated for 800 V repetitive peak off-state voltage and 35 mA maximum gate trigger current. It delivers 2500 V_rms isolation, UL certification (E81734), and supports AC line switching without external snubbers when operated within datasheet limits. Used in fan, pump, solenoid, and heater control in home appliances.

For engineers reviewing the T1635T-8I datasheet, T1635T-8I pinout, T1635T-8I application, or T1635T-8I equivalent, key selection criteria include dV/dt immunity (2000 V/µs at 125 °C), commutation robustness (di/dt_c ≥ 16 A/ms), insulation rating, and gate sensitivity for low-power drive compatibility.

Technical Context

This triac operates across quadrants I, II, and III, enabling bidirectional conduction with gate-triggered turn-on regardless of main terminal polarity. Its snubberless design relies on high critical dV/dt (2000 V/µs) and di/dt_c (16 A/ms at 125 °C) to prevent false triggering and commutation failure during phase-angle or zero-crossing switching.

Thermal performance is defined by R_th(j–c) = 2.1 °C/W and IT(RMS) derating from 16 A at 108 °C case temperature to 12 A at 119 °C. The ceramic-insulated TO-220AB package provides 2500 V_rms isolation and meets RoHS 2002/95/EC and UL E81734 standards.

Key Specifications

Parameter	Value and Actual Design Meaning
IT(RMS)	16 A at Tc = 108 °C - continuous AC load current capability with heatsink
VDRM / VRRM	800 V at Tj = 125 °C - peak blocking voltage for 230 VAC mains with safety margin
IGT (max)	35 mA - maximum gate current required for reliable turn-on across all quadrants
dV/dt (min)	2000 V/µs at Tj = 125 °C - immunity to voltage transients without snubber
(di/dt)c (min)	16 A/ms at Tj = 125 °C - minimum rate of current decrease to sustain turn-off
VTM (max)	1.55 V at ITM = 22.6 A - on-state voltage drop defining conduction loss and thermal rise
Rth(j–c)	2.1 °C/W - junction-to-case thermal resistance for heatsink sizing

Pinout & Package

Package: TO-220AB insulated (ceramic isolation, UL E81734 certified, 2500 V_rms isolation).

Pin/Terminal	Circuit Role	Design Meaning
A1	Main Terminal 1 (MT1)	Reference terminal for gate trigger; defines polarity reference for quadrant operation
A2	Main Terminal 2 (MT2)	Current return path; voltage polarity relative to A1 determines conduction quadrant
G	Gate	Control input; triggers conduction in all three quadrants with ≤35 mA pulse

Key Features

Feature	Design Value
Snubberless operation	Validated up to 2000 V/µs dV/dt and 16 A/ms di/dt_c, eliminating need for external RC networks
Three-quadrant control	Enables gate-triggered turn-on in quadrants I, II, and III - simplifies driver design vs. four-quadrant devices
2500 V_rms isolation	Ceramic-insulated TO-220AB package meets reinforced insulation requirements for Class I appliances
UL certification	Recognized under UL file E81734 - supports regulatory approval for end equipment
RoHS compliance	Fully compliant with EU Directive 2002/95/EC - suitable for environmentally regulated markets

Applications

Fan Speed Control

Pump Motor Switching

Use Scenario: Variable-speed AC induction fan in HVAC or kitchen hood, controlled via phase-angle dimming.

IC Role / Device Role / Timing Role: Main power switch delivering adjustable RMS voltage to motor windings.

Use Value: Enables smooth speed regulation without snubber components, reducing BOM count and board space.

Use Scenario: On/off and soft-start control of AC water pump in washing machine or dishwasher.

IC Role / Device Role / Timing Role: High-current AC load switch handling inrush currents up to 126 A surge.

Use Value: Withstands repeated 126 A surges (60 Hz, 16.7 ms) and maintains stable hold/latch behavior down to 45 mA IH.

Solenoid Actuator Driver

Heater Power Regulation

Use Scenario: Driving 230 VAC solenoid valves in coffee machines or irrigation controllers.

IC Role / Device Role / Timing Role: Zero-crossing or phase-controlled switch managing coil energization timing.

Use Value: High dV/dt immunity prevents false turn-on from coil flyback transients; 35 mA IGT ensures compatibility with MCU GPIOs.

Use Scenario: Power regulation for resistive heating elements in ovens or water heaters.

IC Role / Device Role / Timing Role: Robust AC line switch handling steady 16 A RMS and transient overloads.

Use Value: Low on-state voltage (1.55 V max) minimizes conduction loss and thermal stress at full load.

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
BTB16-800CW	Same 16 A/800 V rating but 50 mA max IGT; non-snubberless; TO-220 non-insulated package	Lacks 2500 V_rms isolation and dV/dt immunity - requires external snubber and creepage/clearance redesign	Select only if isolation and snubberless operation are not required and board layout accommodates lower dV/dt margins
T1635H-8I	Same specs but "H" grade indicates higher dV/dt (2500 V/µs) and improved di/dt_c (20 A/ms); identical TO-220AB insulated package	Enhanced commutation margin for demanding inductive loads or noisy environments	Prefer for industrial-grade reliability where transient immunity exceeds standard T1635T-8I requirements

Compared with BTB16-800CW and T1635H-8I, the T1635T-8I balances snubberless operation, certified isolation, and gate sensitivity for cost-sensitive consumer appliance designs - offering verified dV/dt immunity without over-spec'ing for industrial use cases.

Availability

T1635T-8I is available at Aetrix Electronics and suitable for home appliance control, AC motor switching, and resistive heater regulation requiring stable component supply and long-term production support.

Supply support for T1635T-8I 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 microcontrollers, power devices, sensors, and analog ICs for industrial, automotive, and consumer markets.

The Snubberless™ Triac product line targets cost-effective, reliable AC power control in white goods and building automation - emphasizing simplified design, reduced external components, and regulatory-ready isolation.

FAQ

What is the maximum allowable gate trigger current for reliable operation?

The absolute maximum peak gate current is 4 A for 20 µs pulses at Tj = 150 °C. For continuous triggering, the average gate power dissipation must not exceed 1 W. Typical gate drive uses 100 mA pulses (≥2 µs width) to ensure robust turn-on across all quadrants while staying well within safe operating limits.

Can T1635T-8I be used without a heat sink?

No - at 16 A RMS, junction temperature will exceed 150 °C without heatsinking. At ambient 25 °C with free-air convection, maximum sustainable current is ~2.5 A. For full-rated 16 A operation, a heatsink maintaining Tc ≤ 108 °C (R_th(c–a) ≤ 5.3 °C/W) is mandatory per Figure 2 and Figure 3.

Does the "-8I" suffix indicate 800 V rating and insulated package?

Yes. Per ST's ordering scheme: "8" denotes 800 V VDRM/VRRM rating; "I" specifies TO-220AB insulated package with 2500 V_rms isolation. The "T" indicates triac type; "16" is RMS current rating (16 A); "35" is max IGT in mA. This coding is consistent across ST's Snubberless™ triac family.

How does T1635T-8I differ from T1620T-8I beyond gate sensitivity?

Both share identical package, voltage rating (800 V), current rating (16 A), and isolation (2500 V_rms). The core difference is gate trigger current: T1620T-8I has max IGT = 20 mA, while T1635T-8I is 35 mA. Higher IGT improves noise immunity but requires slightly stronger gate drive - making T1620T-8I preferable for ultra-low-power MCU interfaces.

T1635T-8I Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: Snubberless™

Package/Case:: TO-220-3

Packaging:: Tube

Product Status:: Active

Triac Type:: Alternistor - Snubberless

Voltage - Off State:: 800 V

Current - On State (It (RMS)) (Max):: 16 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):: 45 mA

Configuration:: Single

Operating Temperature:: -40°C ~ 150°C (TJ)

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: TO-220AB Insulated

T1635T-8I FAQ

1.How can I place an order for T1635T-8I through Aetrix?

Please submit a Request for Quotation (RFQ) for T1635T-8I 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 T1635T-8I reliable?

The price and inventory of T1635T-8I are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for T1635T-8I is usually 5 days.

3.What payment methods are accepted for T1635T-8I?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for T1635T-8I transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for T1635T-8I?

T1635T-8I orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your T1635T-8I 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 T1635T-8I?

For technical support, including T1635T-8I datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your T1635T-8I requirements.

6.How does Aetrix verify that T1635T-8I is sourced from the original manufacturer or authorized distributors?

All T1635T-8I 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 T1635T-8I meets industry standards.

7.What is the process for return or replacement of T1635T-8I?

All T1635T-8I units undergo pre-shipment inspection (PSI). If there is an issue with T1635T-8I, 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 T1635T-8I part is unused and in its original packaging.

Return procedure for T1635T-8I:

1.Submit a request within 90 days.

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

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