STMicroelectronics T1635T-6I

Overview

T1635T-6I from STMicroelectronics is a Snubberless™ logic-level triac rated for 16 A RMS on-state current, 600 V repetitive peak off-state voltage (VDRM/VRRM), and 35 mA maximum gate trigger current (IGT) in Quadrant III. It features high dynamic commutation (dV/dt = 2000 V/µs at Tj = 125 °C), low thermal resistance (Rth(j-c) = 2.1 °C/W), and TO-220AB insulated package with 2500 V_rms isolation-designed for reliable phase-angle and on/off AC line switching in motor-driven power tools.

For engineers reviewing the T1635T-6I datasheet, T1635T-6I pinout, T1635T-6I application, or T1635T-6I equivalent, key selection criteria include verified snubberless operation at 125 °C junction temperature, I²t rating of 105 A²s, and gate-trigger robustness across quadrants without external snubbers.

Technical Context

The T1635T-6I is a three-quadrant, bidirectional thyristor optimized for snubberless operation in high-noise AC environments. Its design emphasizes immunity to false triggering via high dV/dt (2000 V/µs at 125 °C) and high di/dt capability (50 A/µs), enabled by clip-bonded construction that reduces thermal resistance and improves surge handling.

It operates across -40 °C to +125 °C junction temperature range with guaranteed IGT ≤ 35 mA in QIII and ≤ 20 mA in QI/QII, and supports full-cycle conduction with IT(RMS) = 16 A at Tc = 86 °C. The device requires no external snubber under standard 50/60 Hz line conditions due to intrinsic dv/dt robustness.

Key Specifications

Pinout & Package

Package: TO-220AB insulated (UL E81734 certified, RoHS-compliant, epoxy UL94 V0). Dimensions per ST DocID16488 Rev 3: 15.9 mm × 10.4 mm × 4.6 mm (L×W×H), 2.3 g weight, 3-pin through-hole mounting with creepage/clearance optimized for 2500 V_rms isolation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BTA16-600BWRG and MAC16A6G, the T1635T-6I uniquely combines snubberless 2000 V/µs dV/dt, 35 mA QIII gate drive, and certified 2500 V_rms isolation-enabling simplified, safety-compliant designs in Class I portable appliances.

Availability

T1635T-6I is available at Aetrix Electronics and suitable for motor control in power tools, dimmable LED lighting systems, and heating element switching in small home appliances requiring stable component supply and long-term industrial availability.

Supply support for T1635T-6I 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, microcontroller, power, and sensor solutions for industrial, automotive, and consumer markets.

The T16T series belongs to ST's Snubberless™ Triac product line, engineered specifically for cost-sensitive, high-reliability AC line switching in white goods and power tools where snubber elimination and thermal efficiency are critical.

FAQ

What is the maximum junction temperature for continuous operation?

The T1635T-6I has a specified operating junction temperature range of -40 °C to +125 °C. Continuous operation at 125 °C is permitted when case temperature is maintained at or below 86 °C per the IT(RMS) derating curve in Figure 2 of ST DocID16488 Rev 3. Exceeding this case temperature requires linear derating of RMS current.

Can it be driven directly by a 3.3 V microcontroller GPIO?

Yes-the T1635T-6I guarantees IGT ≤ 35 mA in Quadrant III and ≤ 20 mA in Quadrants I/II at 25 °C, and maintains ≤ 50 mA IGT up to 125 °C per Figure 8. A 3.3 V GPIO with ≥ 40 mA sink/source capability can drive the gate directly through a current-limiting resistor (e.g., 100 Ω for ~30 mA).

Does it require a heat sink in 16 A applications?

Yes-a heat sink is mandatory. At IT(RMS) = 16 A and Tc = 86 °C, power dissipation reaches ~12 W (VT ≈ 1.55 V × 16 A × 0.636 for sine wave). With Rth(j-c) = 2.1 °C/W, a heatsink with Rth(c-a) ≤ 3.5 °C/W is required to maintain Tj ≤ 125 °C in 50 °C ambient, per thermal calculations in Section 5 of the datasheet.

Is the TO-220AB insulated package UL-certified?

Yes-the T1635T-6I TO-220AB insulated package is UL certified under file E81734, confirming compliance with UL 1557 for reinforced insulation. The 2500 V_rms isolation rating is validated per UL test conditions and applies to the entire package, including creepage and clearance distances.