STMicroelectronics BTA25-700B

Overview

BTA25-700B from STMicroelectronics is a 25 A RMS, 700 V repetitive peak off-state voltage (VDRM/VRRM), snubberless triac in TO-220AB insulated package, designed for phase-controlled AC switching in lighting and motor control circuits with high commutation capability in quadrants I, II, and III. It delivers 1.55 V max on-state voltage at 35 A, supports 50 mA gate trigger current, and operates up to 125 °C junction temperature.

For engineers reviewing the BTA25-700B datasheet, BTA25-700B pinout, BTA25-700B application, or BTA25-700B equivalent, this device is selected for robust, snubberless AC power control where high dV/dt immunity (>1000 V/µs), low thermal resistance (0.8 °C/W j-c), and UL1557 recognition are critical in heating regulation and static relay designs.

Technical Context

This triac implements a three-quadrant snubberless structure optimized for reliable turn-on without external snubbers under high dv/dt stress - achieving ≥1000 V/µs critical rate of rise of off-state voltage at 125 °C. Its gate trigger threshold remains stable across -40 to +125 °C, with guaranteed IGT ≤ 50 mA and VGT ≤ 1.3 V.

Thermally, it features a low junction-to-case thermal resistance of 0.8 °C/W (TO-220AB non-insulated variant) and 1.7 °C/W (insulated variant), enabling 25 A RMS conduction at Tc = 75 °C. The device sustains 250 A non-repetitive surge current (50 Hz, 20 ms) and exhibits 340 A²s I²t fusing value.

Key Specifications

Pinout & Package

Package: TO-220AB insulated - UL94 V0 flammability-rated, halogen-free molding compound, lead-free plating, 2.5 kV RMS insulation rating (1 min), recommended torque 0.55 N·m.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BTA24-700B, the BTA25-700B offers 1 A higher RMS current capacity and tighter thermal margin; versus BTB24-700B, it provides certified reinforced insulation essential for direct mains-connected equipment without additional isolation design effort.

Availability

BTA25-700B is available at Aetrix Electronics and suitable for light dimming systems, heating regulation circuits, static relay modules, and induction motor start circuits requiring stable component supply, long-lifecycle support, and UL-certified isolation.

Supply support for BTA25-700B 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, power, MCU, and sensor solutions for industrial, automotive, and consumer markets.

The BTA25-700B belongs to ST's high-reliability triac product line engineered specifically for robust, snubberless AC power control in safety-critical mains-connected equipment - emphasizing insulation integrity, thermal resilience, and noise immunity.

FAQ

Is BTA25-700B compatible with zero-crossing optotriacs like MOC3041?

Yes - BTA25-700B is commonly driven by zero-crossing optotriacs such as MOC3041 or IL420. Its 50 mA maximum gate trigger current and 1.3 V max VGT ensure reliable turn-on with standard optocoupler output stages. Gate resistor selection must limit peak current to ≤4 A per datasheet spec, and series resistance should be sized to deliver ≥50 mA under worst-case VCC and temperature conditions.

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

The datasheet specifies 25 A RMS operation at Tc = 75 °C for the insulated TO-220AB package. Exceeding 75 °C case temperature requires derating - e.g., at Tc = 85 °C, IT(RMS) drops to ~22 A. Thermal design must ensure heatsink interface resistance and ambient conditions maintain case temperature ≤75 °C under full load and worst-case ambient.

Does BTA25-700B support four-quadrant triggering?

No - BTA25-700B is a snubberless three-quadrant triac, rated for reliable triggering only in quadrants I, II, and III. Quadrant IV triggering is not characterized or guaranteed. For full four-quadrant operation, ST recommends standard variants like BTB24-700B (though uninsulated) or equivalent 4Q triacs with verified IV-quadrant IGT specs.

Can BTA25-700B replace BTA16-600B in an existing design?

Only with verification - BTA25-700B has higher current (25 A vs. 16 A), higher voltage (700 V vs. 600 V), and different thermal resistance (1.7 °C/W vs. ~2.0 °C/W). While electrically backward-compatible in most cases, mechanical fit (same TO-220AB insulated outline) is confirmed, but gate drive energy and heatsink sizing must be re-evaluated due to increased I²R losses and altered thermal path.