STMicroelectronics BTA08-700BRG

Overview

BTA08-700BRG from STMicroelectronics is a snubberless, logic-level triac rated for 8 A RMS on-state current and 700 V repetitive peak off-state voltage (VDRM/VRRM), designed for AC mains switching in phase-control and zero-crossing applications. It features 50 mA maximum gate trigger current (IGT), 1.2 V maximum gate trigger voltage (VGT), and 2500 VRMS insulated tab compliance with UL E81734, enabling direct interface with microcontrollers in motor speed controllers and light dimmers.

For engineers reviewing the BTA08-700BRG datasheet, BTA08-700BRG pinout, BTA08-700BRG application, or BTA08-700BRG equivalent, key selection criteria include commutation robustness on inductive loads, gate drive compatibility with 3.3 V/5 V logic, thermal resistance (Rth(j-c) = 2.5 °C/W for TO-220AB Ins.), and snubberless operation at dV/dt ≥ 400 V/µs.

Technical Context

This triac operates in three quadrants (I, II, III) with snubberless commutation capability, supporting reliable turn-off under high inductive load conditions without external snubbers. Its gate sensitivity (IGT ≤ 50 mA) and low VGT (≤1.2 V) allow direct drive from MCU GPIO pins without buffer stages.

Thermal design is enabled by its insulated TO-220AB package (Rth(j-c) = 2.5 °C/W), rated for junction temperatures up to +125 °C and storage down to –40 °C. Critical commutation parameters include (dl/dt)c ≥ 4.5 A/ms and dV/dt ≥ 400 V/µs at Tj = 125 °C.

Key Specifications

Pinout & Package

Package: TO-220AB Insulated (UL-rated 2500 VRMS insulated tab, ECOPACK2 compliant, lead-free plating).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BTB08-700BRG, BTA08-700BRG trades 1.1 °C/W higher thermal resistance for certified 2500 VRMS isolation-critical for safety-certified industrial equipment. Versus T835-700H, it offers lower gate drive burden and through-hole mounting flexibility at the cost of larger footprint and slightly reduced thermal efficiency.

Availability

BTA08-700BRG is available at Aetrix Electronics and suitable for light dimming systems, motor speed controllers, and static relay modules requiring stable component supply across industrial OEM production cycles.

Supply support for BTA08-700BRG 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, microcontroller, and sensor solutions for industrial, automotive, and consumer markets.

The BTA series belongs to ST's high-reliability snubberless triac product line, engineered specifically for robust AC switching in inductive and resistive load applications where safety isolation and logic-level drive are mandatory.

FAQ

What is the maximum junction temperature for continuous operation?

The BTA08-700BRG has an operating junction temperature range of –40 °C to +125 °C. Continuous operation must maintain Tj ≤ +125 °C under worst-case ambient and power dissipation conditions, verified using Rth(j-c) = 2.5 °C/W and heatsink thermal resistance.

Does this triac require a heat sink in all applications?

Yes-due to its 8 A RMS rating and power dissipation characteristics, a heatsink is required whenever IT(RMS) exceeds ~2 A at ambient temperatures above 40 °C. The insulated TO-220AB package mandates mechanical mounting to a thermally conductive heatsink with torque limited to 0.55 N·m.

Can BTA08-700BRG replace a standard 4-quadrant triac in existing designs?

It can replace 4-quadrant triacs only if the application uses only quadrants I, II, and III-and avoids quadrant IV triggering. Its 3-quadrant architecture reduces EMI and improves commutation but requires gate drive polarity alignment consistent with ST's recommended firing circuit topology.

Is the insulated tab rated for functional or reinforced isolation?

The 2500 VRMS insulated tab is rated for reinforced isolation per UL E81734, meaning it provides both basic and supplementary insulation in a single barrier-suitable for primary-to-secondary safety separation in Class I equipment without additional insulation layers.