STMicroelectronics BTA41-800BRG

Overview

BTA41-800BRG from STMicroelectronics is a 40 A, 800 V RMS insulated triac in TOP3 package, rated for 2500 V_rms isolation between tab and main terminals, designed for AC phase control and on/off switching in industrial power systems. It delivers 50 mA gate trigger current (I_GT), 50 A/µs critical dI/dt, and supports thermal management up to 9 kW with appropriate heatsinking.

For engineers reviewing the BTA41-800BRG datasheet, BTA41-800BRG pinout, BTA41-800BRG application, or BTA41-800BRG equivalent, key selection criteria include insulated tab rating, 800 V off-state blocking voltage, 40 A RMS current capability at T_c = 80 °C, low junction-to-case thermal resistance (0.9 °C/W), and UL 1557 recognition (file ref: 81734).

Technical Context

The BTA41-800BRG is a four-quadrant, standard-sensitivity triac optimized for bidirectional AC conduction without requiring gate polarity reversal. Its insulated TOP3 package enables direct mounting to grounded heatsinks while maintaining 2500 V_rms dielectric strength between A2 terminal and tab.

It operates across -40 °C to +125 °C junction temperature range, supports 420 A non-repetitive surge current (16.7 ms), and features 500 V/µs minimum dV/dt immunity at 125 °C with open gate - enabling robust noise immunity in motor control and dimmer circuits.

Key Specifications

Pinout & Package

Package: TOP3 insulated - epoxy body meeting UL94 V0, lead-free, with insulated metal tab (A2-connected) rated 2500 V_rms isolation. Mounting torque: 1.05 N·m (max 1.2 N·m). Dimensions per DS2111 Rev 13: G ≈ 20.75 mm, F ≈ 16.15 mm, C ≈ 14.98 mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BTA41-800BRG, the BTA41-800B sacrifices isolation for lower cost, while BTB41-800BRG trades isolation for improved thermal performance - making the BTA41-800BRG optimal where safety-certified grounded mounting is mandatory without added BOM complexity.

Availability

BTA41-800BRG is available at Aetrix Electronics and suitable for industrial heating regulation, AC motor starting circuits, and static relay implementations requiring stable component supply, UL certification, and insulated high-current AC switching capability.

Supply support for BTA41-800BRG 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, MCU, power, and sensing solutions for industrial, automotive, and consumer markets.

The BTA41 series belongs to ST's high-power thyristor product line, engineered specifically for robust, certified AC power control in harsh industrial environments where reliability, safety certification, and thermal resilience are non-negotiable.

FAQ

What is the maximum continuous power this triac can switch?

The BTA41-800BRG supports up to 9 kW AC load switching when mounted on a properly sized heatsink maintaining case temperature ≤80 °C. This assumes 400 V AC line voltage and resistive load; actual capacity depends on ambient conditions, heatsink thermal resistance, and duty cycle. Derating is required above 80 °C case temperature per Figure 2 in DS2111.

Can it be used with microcontroller GPIO directly?

No - the 50 mA maximum gate trigger current exceeds typical GPIO drive capability. A buffer stage (e.g., transistor, optocoupler like MOC3021/MOC3041, or dedicated triac driver IC) is required to deliver sufficient gate charge. Gate resistor value must be selected to limit peak current to ≤8 A while ensuring ≥50 mA under worst-case V_CC and temperature.

Does the insulated tab require electrical connection?

Yes - the insulated metal tab is internally connected to A2 and must be electrically tied to the A2 circuit node. Its insulation only applies to the interface between tab and mounting surface; it does not isolate A2 from the rest of the device. Grounding the tab grounds A2 unless isolated via transformer or optocoupler.

How does its dV/dt rating affect circuit design?

A minimum 500 V/µs dV/dt rating means the triac resists false turn-on from fast-rising transients, but snubber networks (RC across A1–A2) are still recommended in inductive loads (e.g., motors) to suppress voltage spikes exceeding V_DRM. Layout best practices - short gate traces, ground plane under A1/A2 - further preserve noise immunity.