STMicroelectronics T1235T-8G-TR

Overview

T1235T-8G-TR from STMicroelectronics is a Snubberless™ 12 A, 800 V RMS three-quadrant triac in D²PAK package, designed for high-commutation AC line switching without external snubber circuits. It delivers 900 V non-repetitive surge capability (VDSM/VRSM), 100 A/µs critical di/dt, and operates up to 150 °C junction temperature-enabling robust motor control and heating applications in compact SMD designs.

For engineers reviewing the T1235T-8G-TR datasheet, T1235T-8G-TR pinout, T1235T-8G-TR application, or T1235T-8G-TR equivalent, key selection criteria include verified dV/dt immunity (≥1000 V/µs at 150 °C), (dl/dt)c ≥6 A/ms at 150 °C, gate trigger current ≤35 mA, on-state voltage ≤1.6 V at 17 A, and thermal resistance Rth(j-c) ≤1.6 °C/W.

Technical Context

This triac employs a three-quadrant structure with gate-triggered turn-on in Quadrants I, II, and III-enabling phase-angle and zero-crossing control in bidirectional AC systems. Its Snubberless™ architecture eliminates need for RC snubbers when operated within specified dV/dt and (dl/dt)c limits, reducing BOM count and PCB area.

Thermal design is supported by low junction-to-case resistance (1.6 °C/W) and extended 150 °C maximum operating junction temperature, allowing higher power density in convection-cooled home appliance and industrial heating modules where ambient temperatures exceed 100 °C.

Key Specifications

Pinout & Package

Package: D²PAK (TO-263AB), UL94-V0 flammability rated, RoHS and halogen-free (Ecopack®2 compliant). Tab is electrically connected to A2.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BTB12-800CW and MAC12N8G, the T1235T-8G-TR offers superior thermal margin (150 °C vs. 125 °C), verified snubberless operation, and higher dV/dt immunity-making it optimal for space-constrained, high-reliability AC switching where board area and component count must be minimized.

Availability

T1235T-8G-TR is available at Aetrix Electronics and suitable for motor control circuits, home appliance heating systems, and lighting dimming applications requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for T1235T-8G-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.

The T1235T-8G-TR belongs to ST's Snubberless™ Triac product line, engineered specifically for high-reliability, snubber-free AC power control in cost-sensitive, thermally constrained applications such as white goods and power tools.

FAQ

Is the T1235T-8G-TR compatible with zero-crossing trigger circuits?

Yes. The device supports both phase-angle and zero-crossing triggering modes due to its three-quadrant gate structure. When used with zero-crossing optocouplers like MOC3041, it ensures minimal EMI and smooth turn-on at voltage minima-ideal for resistive heating and fan speed control where acoustic noise must be minimized.

What is the minimum gate trigger current required at 150 °C junction temperature?

The maximum gate trigger current (IGT) is specified as 35 mA at 25 °C and remains ≤35 mA up to 150 °C per Table 3. Typical IGT decreases with rising temperature, so a 20 mA drive at room temperature provides sufficient margin across the full -40 °C to +150 °C operating range.

Can the T1235T-8G-TR replace a TO-220 triac in an existing design?

Yes, with PCB layout adaptation. The D²PAK package has identical pinout (A2–A1–G) and thermal pad alignment as TO-220 but requires larger copper pour and stencil-defined solder paste for the exposed tab. Thermal performance is superior (Rth(j-c) = 1.6 °C/W vs. ~2.5 °C/W for TO-220), enabling higher power density.

Does the "-TR" suffix indicate tape-and-reel packaging only, or does it affect electrical specs?

The "-TR" suffix denotes tape-and-reel packaging (1000 units per reel) and has no impact on electrical or thermal specifications. All performance parameters-including IT(RMS), VDRM, dV/dt, and (dl/dt)c-are identical to the tube-packaged T1235T-8G. Only mechanical handling and assembly logistics differ.