STMicroelectronics T1625T-8I

Overview

T1625T-8I from STMicroelectronics is a standard 16 A, 800 V repetitive peak off-state voltage (V_DRM/V_RRM) triac in a TO-220AB insulated package, rated for 2500 V_rms insulation and certified to UL E81734. It supports four-quadrant triggering with 25 mA gate trigger current (I_GT) in quadrants I–III and operates in general-purpose AC line switching applications including fan and pump control in home appliances.

For engineers reviewing the T1625T-8I datasheet, T1625T-8I pinout, T1625T-8I application, or T1625T-8I equivalent, key selection criteria include its 16 A RMS on-state current at T_c = 108 °C, 120 A non-repetitive surge rating, ceramic-insulated TO-220AB package, 500 V/µs dV/dt immunity at 125 °C, and compliance with RoHS 2002/95/EC.

Technical Context

The T1625T-8I is a bidirectional thyristor designed for full-cycle AC switching and phase-angle control. Its four-quadrant gate triggering enables reliable turn-on with either polarity of gate signal relative to MT1, supporting universal AC line interface without external polarity conditioning.

It features a low on-state voltage drop (V_TM ≤ 1.55 V at 22.6 A, 25 °C) and dynamic resistance (R_d ≤ 30 mΩ at 150 °C), enabling efficient power handling. Thermal resistance from junction to case is 2.1 °C/W, allowing direct heatsink mounting for sustained 16 A conduction at case temperatures up to 108 °C.

Key Specifications

Pinout & Package

Package: TO-220AB insulated (ceramic isolation between tab and internal die), UL-certified (E81734), RoHS-compliant, epoxy meets UL94 V0.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BT139-600E and MAC16A8G, the T1625T-8I uniquely combines 800 V blocking, 25 mA low-I_GT drive, and certified 2500 V_rms insulation in one RoHS-compliant device-enabling simplified, safety-certifiable designs for global 230 V appliance markets.

Availability

T1625T-8I is available at Aetrix Electronics and suitable for home appliance control, industrial AC load switching, and overvoltage protection circuits requiring stable component supply, long-term manufacturability, and regulatory compliance.

Supply support for T1625T-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, designing and manufacturing analog, digital, and mixed-signal ICs for automotive, industrial, and consumer applications.

The T1625T-8I belongs to ST's high-voltage power discrete portfolio, engineered specifically for reliable, certified AC power control in safety-critical white goods and industrial equipment.

FAQ

What is the maximum case temperature for continuous 16 A operation?

The T1625T-8I supports 16 A RMS continuous conduction at a case temperature (T_c) of 108 °C, as specified in Table 2 of the datasheet. Exceeding this temperature requires derating per Figure 2; at T_c = 119 °C, the rated current drops to 12 A RMS. Thermal design must ensure heatsink-to-case interface resistance and ambient conditions maintain T_c ≤ 108 °C under worst-case load.

Is the TO-220AB insulated package suitable for direct mounting to a grounded metal chassis?

Yes-the TO-220AB insulated package provides 2500 V_rms isolation between the internal die (A1/A2/G) and the external metal tab, verified per UL file E81734. This allows safe mechanical mounting to grounded chassis without additional insulating hardware, provided torque is maintained within 0.4–0.6 N·m and no mechanical stress compromises the ceramic isolation layer.

Does the T1625T-8I support zero-crossing switching?

No-the T1625T-8I is not inherently zero-crossing; it conducts as soon as triggered and remains latched until current falls below holding level (I_H ≤ 35 mA). Zero-crossing operation requires external circuitry (e.g., optotriac + zero-crossing detector) to gate-trigger only near voltage zero. Its 500 V/µs dV/dt rating helps prevent false triggering during zero-crossing transitions.

Can the T1625T-8I replace the T1625T-6I in an existing design?

Only if the application operates at ≤600 V peak line voltage. The T1625T-8I has 800 V V_DRM/V_RRM (vs. 600 V for -6I), offering higher voltage margin for 230 V AC mains with transients. Pinout, package, and thermal specs are identical; gate trigger current (25 mA) and on-state characteristics match. No layout or drive changes are needed for upgrade.