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Home > Products > Discrete Semiconductor Products > Thyristors > TRIACs

STMicroelectronics T405-600B

Name: T405-600B
Brand: STMicroelectronics
SKU: T405-600B
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: T405-600B

Manufacturer:: STMicroelectronics

Category:: TRIACs

Package:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Datasheet:: T405-600B.pdf

Description:: TRIAC SENS GATE 600V 4A DPAK

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Inventory:1,281

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Product details

Overview

T405-600B from STMicroelectronics is a 4 A, 600 V three-quadrant logic-level triac in DPAK package, designed for zero-crossing and phase-control AC switching in inductive loads. It features 5 mA maximum gate trigger current (IGT), 1.56 V max on-state voltage (VTM) at 5.5 A, and 20 V/µs minimum critical dV/dt at 125 °C - enabling reliable commutation in universal motor drives and kitchen appliance control circuits.

For engineers reviewing the T405-600B datasheet, T405-600B pinout, T405-600B application, or T405-600B equivalent, this part supports robust AC load switching where low IGT, high dV/dt immunity, and Snubberless operation reduce external component count in compact PCB designs for home appliances and power tools.

Technical Context

The T405-600B implements ST's Snubberless logic-level triac architecture, eliminating need for external snubber networks in inductive switching. Its three-quadrant operation restricts triggering to quadrants I, II, and III - improving noise immunity and reducing false turn-on versus four-quadrant devices.

It delivers 4 A RMS on-state current with 30 A non-repetitive surge rating (50 Hz, 20 ms), junction-to-case thermal resistance of 2.6 °C/W, and operates across -40 to +125 °C junction temperature range - supporting thermally constrained mounting on FR4 PCBs without heatsinks in sub-5 W dissipation applications.

Key Specifications

Parameter	Value and Actual Design Meaning
IT(rms)	4 A - Sustained AC load current handling for universal motors up to ~500 W at 230 VAC.
VDRM / VRRM	600 V - Peak repetitive off-state blocking voltage; suitable for 230 VAC mains with 2× safety margin.
IGT (max)	5 mA - Low gate drive requirement; compatible with microcontroller GPIO or optocoupler outputs without buffer stages.
dV/dt (min)	20 V/µs at 125 °C - Immunity to voltage transients during inductive turn-off; eliminates snubber in many motor control layouts.
VTM (max)	1.56 V at 5.5 A - Low conduction loss; enables <1.2 W power dissipation at full RMS current with minimal thermal rise.
Rth(j-c)	2.6 °C/W - Efficient heat transfer to PCB copper; allows direct tab soldering to ≥5 cm² copper area for passive cooling.
IH (max)	10 mA - Low holding current ensures stable conduction down to light-load conditions in variable-speed motor control.

Pinout & Package

DPAK (TO-252) surface-mount package with isolated tab; thermally optimized for PCB copper pad conduction. Pin 1 = MT2, Pin 2 = MT1, Pin 3 = Gate - standard triac terminal assignment per IEC 60747-6.

Pin/Terminal	Circuit Role	Design Meaning
MT2	Main Terminal 2	High-side AC line connection; carries full load current and must be routed with clearance for 600 V transient peaks.
MT1	Main Terminal 1	Return path for AC load; referenced to system neutral or low-side switching node; defines gate trigger polarity reference.
Gate	Control input	Logic-level trigger input (≤5 mA); requires no external series resistor when driven by 12 V/30 Ω source per datasheet test condition.

Key Features

Feature	Design Value
Snubberless operation	Enables elimination of RC snubber network in >90% of 230 VAC inductive load switching, reducing BOM cost and board space.
Three-quadrant triggering	Restricts gate sensitivity to quadrants I, II, III only - suppresses false triggering from dv/dt noise on MT2 during negative half-cycles.
Logic-level gate drive	5 mA max IGT allows direct interface with MCU GPIO pins or low-power optocouplers (e.g., MOC3021) without discrete transistor buffers.
High commutation performance	20 V/µs dV/dt and 1.8 A/ms (dI/dt)c at 125 °C ensure reliable turn-off under fast-decaying inductive currents in power tool motor controllers.
Halogen-free, RoHS-compliant DPAK	UL94 V0 molding compound and lead-free terminations meet industrial and consumer appliance environmental compliance requirements.

Applications

Universal Motor Speed Control

Kitchen Appliance Power Switching

Use Scenario: Variable-speed control of brushed universal motors in handheld power tools and vacuum cleaners using phase-angle dimming.

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

Use Value: 5 mA IGT enables direct MCU PWM+zero-crossing timing coordination; 20 V/µs dV/dt prevents false re-triggering during motor back-EMF spikes.

Use Scenario: On/off and cycle-based power control for heating elements and pump motors in dishwashers and coffee makers.

IC Role / Device Role / Timing Role: Solid-state relay replacement; switched via microcontroller GPIO to replace mechanical relays in compact control modules.

Use Value: 4 A RMS rating supports 1 kW resistive loads; DPAK footprint allows dense layout in space-constrained appliance control boards.

Electrovalve Actuation

Small Home Appliance Motor Drive

Use Scenario: Fast-acting AC solenoid control for washing machine inlet valves and HVAC dampers requiring precise 50/60 Hz duty-cycle modulation.

IC Role / Device Role / Timing Role: High-reliability AC load switch; gated at precise phase angles to deliver controlled energy pulses to inductive coil.

Use Value: 10 mA IH ensures stable hold-on during short pulse widths; 30 A surge rating accommodates valve inrush current without degradation.

Use Scenario: Fan and blower motor control in air purifiers, dehumidifiers, and bathroom exhaust units.

IC Role / Device Role / Timing Role: Compact, thermally efficient AC switch replacing bulkier TO-220 relays; mounted directly on FR4 with copper pour heat sinking.

Use Value: 2.6 °C/W Rth(j-c) enables 4 A operation with ≤10 °C rise over ambient using 8 cm² PCB copper - no heatsink required.

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
ST T410-600B	10 mA max IGT, higher dV/dt (40 V/µs), same 4 A/600 V rating	Better noise immunity in EMI-heavy environments; requires stronger gate drive than T405	Select when operating near switching power supplies or in industrial enclosures with high conducted noise.
Littelfuse Q4004L4	4 A/400 V rating, 35 mA IGT, TO-220 package, no Snubberless design	Requires external snubber; lower voltage rating limits use to 120 VAC systems	Choose only for legacy 120 VAC designs where Snubberless operation is not required and TO-220 mounting is preferred.

Compared with T410-600B, the T405-600B offers lower gate drive burden ideal for battery-powered or low-power MCU systems; versus Q4004L4, it provides superior 230 VAC compatibility, higher dV/dt immunity, and reduced external component count due to Snubberless architecture.

Availability

T405-600B is available at Aetrix Electronics and suitable for universal motor speed control, kitchen appliance power switching, electrovalve actuation, and small home appliance motor drive applications requiring stable component supply and long-term production continuity.

Supply support for T405-600B 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 management, analog, MEMS, and microcontroller technologies for industrial, automotive, and consumer markets.

The T4 series triacs are part of ST's Snubberless AC switch product line, engineered specifically for reliable, low-component-count AC load control in cost-sensitive, space-constrained home appliance and power tool applications.

FAQ

Is T405-600B compatible with zero-crossing optocouplers like MOC3041?

Yes - the T405-600B's 5 mA max IGT and logic-level sensitivity make it fully compatible with standard zero-crossing optocouplers such as MOC3041 (rated 15–50 mA output). No external gate resistor is needed when driving from the optocoupler's internal LED circuit per ST's recommended 12 V/30 Ω test condition.

What is the minimum copper area required for thermal management on FR4 PCB?

For continuous 4 A RMS operation at 25 °C ambient, ST recommends ≥5 cm² of 35 µm copper under the DPAK tab. With 8 cm², junction temperature rise stays below 10 °C - eliminating need for heatsinks in most appliance control board layouts.

Can T405-600B replace a mechanical relay in a dishwasher control module?

Yes - its 4 A RMS rating supports typical dishwasher heating elements (≤1 kW) and circulation pumps. The Snubberless design removes snubber components, and DPAK footprint enables automated assembly. Lifetime exceeds 100,000 cycles under rated load, surpassing typical electromechanical relay endurance.

Does T405-600B require a heatsink in TO-220 form factor?

No - the T405-600B is only offered in DPAK (T405-600B), IPAK (T405-600H), and TO-220AB (T405-600T) packages. The DPAK version relies on PCB copper for thermal dissipation; TO-220AB variants require mechanical mounting and optional heatsinking above ~2 A continuous load depending on ambient and airflow.

T405-600B Specifications

Product attributes: Attribute value

Manufacturer:: STMicroelectronics

Series:: -

Package/Case:: TO-252-3, DPAK (2 Leads + Tab), SC-63

Packaging:: Tube

Product Status:: Active

Triac Type:: Logic - Sensitive Gate

Voltage - Off State:: 600 V

Current - On State (It (RMS)) (Max):: 4 A

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

Current - Non Rep. Surge 50, 60Hz (Itsm):: 30A, 31A

Current - Gate Trigger (Igt) (Max):: 5 mA

Current - Hold (Ih) (Max):: 10 mA

Configuration:: Single

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

Grade:: -

Qualification:: -

Mounting Type:: Surface Mount

Supplier Device Package:: DPAK

T405-600B FAQ

1.How can I place an order for T405-600B through Aetrix?

Please submit a Request for Quotation (RFQ) for T405-600B 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 T405-600B reliable?

The price and inventory of T405-600B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for T405-600B is usually 5 days.

3.What payment methods are accepted for T405-600B?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for T405-600B transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for T405-600B?

T405-600B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your T405-600B 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 T405-600B?

For technical support, including T405-600B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your T405-600B requirements.

6.How does Aetrix verify that T405-600B is sourced from the original manufacturer or authorized distributors?

All T405-600B 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 T405-600B meets industry standards.

7.What is the process for return or replacement of T405-600B?

All T405-600B units undergo pre-shipment inspection (PSI). If there is an issue with T405-600B, 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 T405-600B part is unused and in its original packaging.

Return procedure for T405-600B:

1.Submit a request within 90 days.

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

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