STMicroelectronics T2535T-8I

Overview

T2535T-8I from STMicroelectronics is a 25 A, 800 V RMS-rated insulated TRIAC in TO-220AB package, designed for phase-angle and on/off AC line switching in high-reliability home appliance controls. It delivers 900 V non-repetitive surge capability, 150 °C maximum junction temperature operation, and robust dI/dt commutation (≥18 A/ms at Tj = 150 °C), enabling direct motor and heater load control without external snubbers.

For engineers reviewing the T2535T-8I datasheet, T2535T-8I pinout, T2535T-8I application, or T2535T-8I equivalent, key selection criteria include insulation rating (2.5 kV RMS), gate trigger current (35 mA max), static dV/dt immunity (≥1000 V/µs at 150 °C), and UL1557-compliant isolation - critical for safety-certified AC power stages in consumer and industrial equipment.

Technical Context

This T-series Snubberless TRIAC operates across all four quadrants with verified triggering in I, II, and III. Its internal ceramic-insulated TO-220AB package provides galvanic isolation up to 2.5 kV RMS, meeting UL1557 requirements without external barrier components.

The device sustains 25 A RMS at case temperature TC = 101 °C, with thermal resistance Rth(j–c) ≤ 1.7 °C/W. Dynamic performance includes minimum commutation dI/dt of 18 A/ms at 150 °C and static dV/dt ≥1000 V/µs under worst-case blocking conditions, ensuring noise-immune turn-off in noisy AC environments.

Key Specifications

Pinout & Package

TO-220AB insulated package with integral ceramic isolation barrier between leads and heat sink mounting surface. Mounting tab (A2) is electrically isolated from pins A1 and G, rated for 2.5 kV RMS working voltage.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BTB24-800CW and Q6025LH4, the T2535T-8I uniquely combines UL-recognized 2.5 kV isolation, 150 °C operation, and 900 V surge rating - making it the only option qualified for high-end, safety-certified, thermally demanding home appliance designs without design compromises.

Availability

T2535T-8I is available at Aetrix Electronics and suitable for water heater control, e-bidet thermal management, and universal motor speed regulation requiring stable component supply and long-term lifecycle support.

Supply support for T2535T-8I 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, specializing in power, analog, MEMS, and microcontroller technologies for industrial, automotive, and consumer markets.

The T-series TRIAC product line targets high-reliability AC power control in safety-critical home appliances, emphasizing snubberless operation, extended temperature range, and regulatory-compliant insulation.

FAQ

What is the maximum allowable case temperature for continuous 25 A RMS operation?

The datasheet specifies IT(RMS) = 25 A at TC = 101 °C under full-sine-wave conditions. Operation above this temperature requires linear derating per Figure 2; at TC = 125 °C, maximum sustainable current drops to approximately 18 A RMS. Heatsink design must maintain TC ≤ 101 °C under worst-case ambient and airflow conditions.

Does the T2535T-8I require a snubber network for universal motor loads?

No. The device's guaranteed (dI/dt)c ≥18 A/ms at 150 °C and ≥28 A/ms at 125 °C eliminates the need for external snubbers in typical universal motor applications, as confirmed by ST's Snubberless architecture validation in DS13445. Only highly inductive loads with extreme commutation stress may warrant optional damping.

Can the insulated tab (A2) be directly mounted to a grounded metal chassis?

Yes. The TO-220AB insulated package provides 2.5 kV RMS isolation between the A2 tab and pins A1/G, permitting direct mounting to grounded chassis without additional insulation. This satisfies reinforced insulation requirements per IEC 60335-1 when used with appropriate creepage/clearance spacing on the PCB.

How does the 35 mA maximum IGT affect microcontroller interfacing?

A 35 mA max IGT allows direct drive from standard 3.3 V or 5 V MCU GPIOs with appropriate series resistance (e.g., 150 Ω for 5 V → ~33 mA). For enhanced noise immunity, optocouplers like MOC3021 (15 mA IFT) are commonly used - their output stage easily exceeds the 5–35 mA IGT range across all operating temperatures.