STMicroelectronics T1635-800G-TR

Overview

T1635-800G-TR from STMicroelectronics is a Snubberless™ 16 A, 800 V RMS TRIAC in D²PAK surface-mount package, designed for high-commutation AC mains switching in inductive loads. It features 35 mA gate trigger current (IGT), 1000 V/µs critical dV/dt (Tj = 125 °C), and insulated thermal performance with Rth(j-c) = 1.2 °C/W - enabling reliable phase-angle control in motor speed controllers without external snubbers.

For engineers reviewing the T1635-800G-TR datasheet, T1635-800G-TR pinout, T1635-800G-TR application, or T1635-800G-TR equivalent, key selection criteria include its 3-quadrant Snubberless™ operation, TO-220AB/D²PAK-compatible thermal design, UL1557-certified insulation (2500 VRMS), and suitability for high-noise industrial AC load switching where commutation robustness is critical.

Technical Context

This device operates as a bidirectional thyristor switch for AC line-frequency (50/60 Hz) power control. Its 3-quadrant triggering excludes quadrant II, reducing false turn-on risk under noisy conditions while maintaining full half-cycle conduction capability. The internal ceramic insulation enables direct heatsink mounting without isolation hardware.

Thermal design centers on low junction-to-case resistance (1.2 °C/W) and optimized copper pad layout per Figure 15. Electrical robustness derives from high dV/dt immunity (1000 V/µs at 125 °C) and 8.5 A/ms critical di/dt rating - both validated under worst-case inductive load commutation stress.

Key Specifications

Pinout & Package

D²PAK (TO-263) surface-mount package with exposed metal tab serving as MT2 terminal and thermal path. Tab is electrically isolated from die via internal ceramic layer.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar TRIAC-based AC switching applications.

Compared with BTA16-800CW, T1635-800G-TR offers superior thermal performance and smaller footprint but requires reflow-compatible layout; versus T1650-800G-TR, it trades 15 mA IGT headroom for lower gate drive power and tighter timing control in microcontroller-driven phase-angle systems.

Availability

T1635-800G-TR is available at Aetrix Electronics and suitable for industrial motor speed controllers, smart appliance dimmers, static relay replacements, and heating element regulators requiring stable component supply across multi-year production cycles.

Supply support for T1635-800G-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, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer markets.

This TRIAC belongs to ST's Snubberless™ power switching portfolio, engineered specifically for robust, maintenance-free AC load control in cost-sensitive industrial and white-goods applications where reliability under inductive stress is non-negotiable.

FAQ

What is the maximum allowable junction temperature for continuous operation?

The T1635-800G-TR has an operating junction temperature range of –40 °C to +125 °C. Continuous operation at 125 °C requires strict adherence to derating curves in Figure 3: at Tc = 86 °C, IT(RMS) must be limited to 16 A; above that case temperature, current must be linearly reduced to prevent thermal runaway.

Can this TRIAC be used without a heatsink in low-duty-cycle applications?

No heatsink is strictly mandatory only if power dissipation remains below 1.2 W (calculated as IT² × RD, where RD = 25 mΩ). At 16 A RMS, conduction loss alone exceeds 6.4 W - requiring a heatsink with ≤16.7 °C/W ambient thermal resistance. PCB copper area alone (per Figure 4) supports only ~3.5 A in still air.

Does the "G" in the part number indicate gate sensitivity or package type?

The "G" denotes D²PAK (TO-263) package per ST's ordering scheme (Figure 17); gate sensitivity is encoded separately as "35" (35 mA IGT). This distinguishes it from TO-220AB variants like BTA16-800CW, which share identical electrical specs but different mechanical form factor and thermal behavior.

Is the 2500 VRMS isolation rating certified for reinforced insulation per IEC 60747-5-5?

Yes - the device carries UL1557 certification (file E81734), which aligns with IEC 60747-5-5 requirements for reinforced insulation. This permits use in applications requiring double insulation without additional barrier materials, provided creepage and clearance distances on the PCB meet end-equipment standards (e.g., EN 60335).