My Inquiry
My Account
STMicroelectronics T435-800H
- Part No.:
- T435-800H
- Manufacturer:
- STMicroelectronics
- Category:
- TRIACs
- Package:
- TO-251-3 Short Leads, IPAK, TO-251AA
- Datasheet:
-
T435-800H.pdf
- Description:
- TRIAC ALTERNISTOR 800V 4A TO251
- Quantity:
- Payment:
- Shipping:
Inventory:1,171
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
T435-800H from STMicroelectronics is a 4 A, 800 V snubberless three-quadrant triac in IPAK package, designed for robust AC switching in inductive loads with high commutation performance and low gate trigger sensitivity (IGT ≤ 35 mA). It operates reliably up to 125 °C junction temperature and delivers 1.56 V on-state voltage at 5.5 A, enabling efficient motor control in power tools and kitchen appliances.
For engineers reviewing the T435-800H datasheet, T435-800H pinout, T435-800H application, or T435-800H equivalent, this device is selected for high-noise immunity AC load switching where dV/dt capability ≥ 400 V/µs, I²t rating of 5.1 A²s, and thermal resistance Rth(j-c) = 2.6 °C/W are critical for snubberless operation in universal motor drives.
Technical Context
The T435-800H uses ST's Snubberless logic-level technology, supporting triggering in all three quadrants without external snubbers. Its dV/dt immunity reaches 400 V/µs at 125 °C and critical rate of rise of on-state current (dI/dt) is rated at 50 A/µs under specified gate drive conditions.
It features a low threshold voltage (Vt0 ≤ 0.89 V) and dynamic resistance (Rd ≤ 120 mΩ) at 125 °C, ensuring stable conduction across temperature. The device sustains repetitive surge currents up to 31 A (60 Hz, 16.7 ms) and non-repetitive surges of 30 A (50 Hz, 20 ms).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| IT(rms) | 4 A - Continuous RMS current handling for universal motor loads without derating beyond 110 °C case temperature. |
| VDRM / VRRM | 800 V - Peak repetitive off-state blocking voltage, enabling direct use on 230 VAC mains with margin for transients. |
| IGT (max) | 35 mA - Maximum gate trigger current required for reliable turn-on, compatible with microcontroller GPIOs via simple resistor drive. |
| dV/dt (min) | 400 V/µs - Minimum rate of voltage rise the device withstands without false triggering, eliminating need for snubber networks. |
| I²t (fusing) | 5.1 A²s - Single-pulse energy withstand capability, defining fuse coordination and short-circuit protection design. |
| Rth(j-c) | 2.6 °C/W - Junction-to-case thermal resistance, enabling precise heatsink sizing for IPAK-mounted designs at full 4 A load. |
| VTM | 1.56 V - Maximum on-state voltage at 5.5 A, directly determining conduction loss (P ≈ 1.56 V × IT) and thermal design. |
Pinout & Package
Package: IPAK (TO-251AA), insulated leadframe, halogen-free epoxy, lead-free, recommended mounting torque 0.4–0.6 N·m.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A1 (MT1) | Main Terminal 1 | Reference terminal for gate drive and load return path; connected to neutral or low-side AC line in phase-control circuits. |
| A2 (MT2) | Main Terminal 2 | High-side AC load connection; carries full load current and must be routed with creepage/clearance compliance for 800 V isolation. |
| G | Gate | Control input requiring ≥5 V pulse with ≥35 mA peak to ensure turn-on in all quadrants; sensitive to noise due to snubberless architecture. |
Key Features
| Feature | Design Value |
|---|---|
| Snubberless operation | Rated dV/dt ≥ 400 V/µs eliminates external RC snubber components, reducing BOM count and PCB area in AC motor drivers. |
| Three-quadrant triggering | Guaranteed turn-on in Quadrants I, II, and III enables full-wave phase control with simplified gate drive circuitry. |
| High commutation performance | IL ≤ 50 mA and IH ≤ 35 mA ensure reliable turn-off during zero-crossing and prevent false re-triggering in inductive loads. |
| Extended junction temperature | Rated operation up to 125 °C junction enables compact thermal design in enclosed appliances without forced cooling. |
Applications
| Power Tools | Kitchen Appliances |
|---|---|
|
Use Scenario: Variable-speed control of universal motors in drills, sanders, and grinders using phase-angle firing. IC Role / Device Role / Timing Role: Main AC power switch executing bidirectional conduction synchronized to AC zero-crossing for smooth torque regulation. Use Value: Snubberless dV/dt immunity prevents false triggering from motor back-EMF spikes, improving reliability over 10⁵ operational cycles. |
Use Scenario: On/off and speed control of induction motors in blenders, food processors, and dishwashers. IC Role / Device Role / Timing Role: High-voltage AC switch interfacing microcontroller PWM outputs to 230 VAC motor windings. Use Value: 4 A RMS rating and 31 A surge capability support intermittent high-torque startup loads without thermal shutdown. |
| Home Heating Controls | Electrovalve Actuation |
|
Use Scenario: Solid-state replacement of mechanical relays in electric radiator thermostats and fan coil units. IC Role / Device Role / Timing Role: Zero-crossing switched AC power controller managing resistive heating element duty cycle. Use Value: Low IGT (≤35 mA) allows direct drive from low-power MCU pins, reducing gate driver component count and cost. |
Use Scenario: Fast-acting AC solenoid control in washing machine inlet valves and HVAC zone dampers. IC Role / Device Role / Timing Role: High-dV/dt tolerant switch enabling rapid valve actuation without snubber-induced delay. Use Value: 50 A/µs dI/dt rating ensures clean turn-on edge for precise timing of fluid flow initiation within 10 ms. |
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 |
|---|---|---|---|
| BT139-800 | 4 A, 800 V, 50 mA IGT, TO-220 package, no snubberless rating (dV/dt = 100 V/µs) | Requires external snubber network; higher gate drive demand limits direct MCU interface. | Select when legacy TO-220 footprint is mandatory and board space permits snubber components. |
| T435-800T | Identical electrical specs, but in TO-220AB package with insulated tab and higher Rth(j-a) = 60 °C/W | Better creepage for safety-critical mains isolation; requires larger heatsink for same 4 A load. | Select when reinforced insulation and regulatory certification (e.g., UL, EN 60730) are required over thermal efficiency. |
Compared with BT139-800, T435-800H offers snubberless operation and lower gate drive, simplifying design; versus T435-800T, it provides superior thermal performance in IPAK while sacrificing insulation-ideal for space-constrained, thermally demanding motor controls.
Availability
T435-800H is available at Aetrix Electronics and suitable for power tools, kitchen appliances, and electrovalve actuation requiring stable component supply across industrial production lifecycles.
Supply support for T435-800H 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, and microcontroller solutions for industrial, automotive, and consumer markets.
The T4 series triacs are part of ST's power discrete portfolio, engineered specifically for snubberless AC inductive load switching in cost-sensitive, high-volume appliance and power tool applications.
FAQ
What is the maximum junction temperature for continuous operation of T435-800H?
The T435-800H is rated for continuous operation up to 125 °C junction temperature, as confirmed in Table 3 of the official datasheet (DocID7699 Rev 9). This rating applies under specified thermal conditions with case temperature maintained at or below 110 °C, and must be validated using Rth(j-c) = 2.6 °C/W in thermal modeling.
Can T435-800H be driven directly by a 3.3 V microcontroller GPIO?
No-T435-800H requires minimum 5 V gate pulse and up to 35 mA peak current for guaranteed turn-on across all quadrants. A 3.3 V GPIO cannot meet VGT (≤1.3 V) and IGT (≤35 mA) simultaneously without external amplification; a transistor buffer or dedicated triac driver IC is required.
Is a heatsink required for T435-800H operating at 4 A RMS?
Yes-a heatsink is mandatory. At 4 A RMS and 1.56 V VTM, conduction loss exceeds 6 W. With Rth(j-c) = 2.6 °C/W and max Tj = 125 °C, even at 25 °C ambient, junction temperature would exceed 125 °C without heatsinking; a heatsink maintaining Tc ≤ 110 °C is essential per Figure 2.
Does T435-800H support phase-control dimming of incandescent lamps?
Yes-it supports leading-edge phase-control dimming, but lamp filament inrush current must be limited. With 30 A non-repetitive surge rating and 5.1 A²s I²t, it handles typical 10× cold-filament surges. However, zero-crossing switching is preferred for lamp longevity; phase-control requires careful gate timing to avoid audible noise.
T435-800H Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Series:
- Snubberless™
- Package/Case:
- TO-251-3 Short Leads, IPAK, TO-251AA
- Packaging:
- Tube
- Product Status:
- Active
- Triac Type:
- Alternistor - Snubberless
- Voltage - Off State:
- 800 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):
- 35 mA
- Current - Hold (Ih) (Max):
- 35 mA
- Configuration:
- Single
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-251 (IPAK)
T435-800H FAQ
1.How can I place an order for T435-800H through Aetrix?
Please submit a Request for Quotation (RFQ) for T435-800H 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 T435-800H reliable?
The price and inventory of T435-800H are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for T435-800H is usually 5 days.
3.What payment methods are accepted for T435-800H?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for T435-800H transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for T435-800H?
T435-800H orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your T435-800H 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 T435-800H?
For technical support, including T435-800H datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your T435-800H requirements.
6.How does Aetrix verify that T435-800H is sourced from the original manufacturer or authorized distributors?
All T435-800H 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 T435-800H meets industry standards.
7.What is the process for return or replacement of T435-800H?
All T435-800H units undergo pre-shipment inspection (PSI). If there is an issue with T435-800H, 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 T435-800H part is unused and in its original packaging.
Return procedure for T435-800H:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
T435-800H Tags
-
Z0103NN5AA4
STMicroelectronics
-
Z0107MNT1G
Littelfuse Inc.
-
Z0103MNT1G
Littelfuse Inc.
;;2.jpg)
-
T405-800B-TR
STMicroelectronics
-
T835-600B-TR
STMicroelectronics
.JPG)
-
2N6073BG
Littelfuse Inc.
-
2N6075BG
Littelfuse Inc.
-
BTA08-600CWRG
STMicroelectronics
-
T835H-6G-TR
STMicroelectronics
-
BTA16-800BRG
STMicroelectronics
-
T1210-800G-TR
STMicroelectronics
-
MAC4DHMT4G
Littelfuse Inc.
Tech Hub
Schmitt triggers use separate rising and falling thresholds to stabilize slow or noisy signals. This guide covers hysteresis, 74HC14 and 74HCT14 selection, comparator calculations, RC oscillators and p…
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
