STMicroelectronics T435T-600FP

Overview

T435T-600FP from STMicroelectronics is a 4 A, 600 V Snubberless™ triac in TO-220FPAB package, designed for AC mains switching in power tools, motor speed controllers, and electrovalves. It delivers 35 mA gate trigger current, 750 V/µs dV/dt immunity at 125 °C, and 50 A/µs critical dI/dt rating without external snubbers.

For engineers reviewing the T435T-600FP datasheet, T435T-600FP pinout, T435T-600FP application, or T435T-600FP equivalent, key selection criteria include snubberless commutation robustness, 2.0 kV rms insulation rating, 32 A non-repetitive surge current, and compatibility with 3-quadrant triggering in high-noise industrial AC loads.

Technical Context

This triac operates in three quadrants (I, II, III) with guaranteed 35 mA max gate trigger current and 1.3 V max gate trigger voltage at 25 °C. Its Snubberless architecture enables reliable turn-off under high dI/dt (50 A/µs) and high dV/dt (750 V/µs) conditions without external RC networks.

Thermal design is supported by 4.3 °C/W junction-to-case resistance and 125 °C maximum operating junction temperature. The device features UL-certified 2.0 kV rms isolation and meets RoHS and ECOPACK®2 environmental standards.

Key Specifications

Pinout & Package

TO-220FPAB package with insulated tab (UL 2.0 kV rms), lead-free, RoHS-compliant, ECOPACK®2 certified. Dimensions: 10.2 mm height × 15.9 mm width × 30.1 mm length; mounting hole Ø3.1 mm.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triac switching applications.

Compared with BTA41-600B and BT139-600E, T435T-600FP uniquely combines snubberless operation, UL 2.0 kV insulation, and precise 4 A rating-making it optimal for compact, safety-certified power tool designs where board space and reliability are prioritized over raw current headroom.

Availability

T435T-600FP is available at Aetrix Electronics and suitable for power tools, motor speed controllers, kitchen electrovalves, and light dimmers requiring stable component supply across industrial production cycles.

Supply support for T435T-600FP 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, MCU, power, and sensor solutions for industrial, automotive, and consumer markets.

The T435T-600FP belongs to ST's Snubberless™ triac product line, engineered specifically for robust, simplified AC switching in portable and mains-powered equipment where reliability, safety certification, and reduced bill-of-materials are critical.

FAQ

Is T435T-600FP compatible with zero-crossing trigger circuits?

No - T435T-600FP is optimized for phase-angle control, not zero-crossing operation. Its 35 mA IGT and 750 V/µs dV/dt rating support reliable triggering at arbitrary points in the AC cycle. For zero-crossing applications, ST recommends dedicated ZC triacs like the BT134 series with integrated zero-detection circuitry.

What is the maximum allowable case temperature for continuous 4 A operation?

The datasheet specifies IT(RMS) = 4 A at Tc = 105 °C. Exceeding this temperature risks thermal runaway due to increased on-state voltage and reduced holding current. A heatsink maintaining Tc ≤ 105 °C under worst-case ambient and airflow conditions is mandatory for sustained 4 A conduction.

Does the TO-220FPAB package require electrical isolation from the heatsink?

Yes - although the TO-220FPAB features an insulated tab rated for 2.0 kV rms, mechanical mounting must maintain minimum creepage (≥4.0 mm) and clearance (≥2.5 mm) per IEC 60335. Use UL-listed insulating pads or shoulder washers; do not rely solely on thermal compound for isolation.

Can T435T-600FP replace older T435-600 devices in existing designs?

Yes - T435T-600FP is a direct drop-in replacement for T435-600, sharing identical pinout, ratings, and TO-220FPAB footprint. Key improvements include enhanced dV/dt immunity (750 V/µs vs. 600 V/µs) and updated ECOPACK®2 compliance; no layout or firmware changes are needed.