STMicroelectronics BTA41-400BRG

Overview

BTA41-400BRG from STMicroelectronics is a 40 A, 600 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 heating, motor speed control, and static relay applications.

For engineers reviewing the BTA41-400BRG datasheet, BTA41-400BRG pinout, BTA41-400BRG application, or BTA41-400BRG equivalent, this device supports high-current AC switching up to 9 kW with verified thermal resistance (R_th(j-c) = 0.9 °C/W), low gate trigger current (I_GT ≤ 50 mA), and UL 1557 recognition (file ref: 81734).

Technical Context

The BTA41-400BRG is a four-quadrant sensitive-gate triac optimized for zero-crossing and phase-angle control in 50/60 Hz AC systems. It features guaranteed I_GT ≤ 50 mA across all quadrants at 25 °C, dV/dt immunity ≥ 500 V/µs at 125 °C, and critical dI/dt rating of 50 A/µs under specified gate drive conditions.

Its isolated TOP3 package enables direct heatsink mounting without additional insulation, supporting safe operation at T_j = −40 to +125 °C and case temperature up to 80 °C at full 40 A RMS conduction. Thermal derating follows Figure 2 in DS2111 Rev 13.

Key Specifications

Pinout & Package

Package: TOP3 insulated (plastic housing with electrically isolated metal tab). Dimensions per Table 5 (DS2111 Rev 13): 20.4–21.1 mm length × 15.1–15.5 mm width × 4.4–4.6 mm height; M4 mounting screw; recommended torque 1.05 N·m.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BTA41-400BRG, BTA41-600BRG offers identical electrical and safety performance, while BTB41-600BRG sacrifices isolation for lower cost-making the BTA41 series preferred for UL-compliant industrial controls requiring 2500 V_rms barrier integrity.

Availability

BTA41-400BRG is available at Aetrix Electronics and suitable for industrial heating control, light dimming systems, and static relay replacement requiring stable component supply, long-term lifecycle support, and UL-recognized safety compliance.

Supply support for BTA41-400BRG 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 BTA41 belongs to ST's high-power triac product line engineered specifically for robust, certified AC power control in safety-critical industrial equipment and energy-efficient lighting systems.

FAQ

What is the maximum continuous power dissipation for BTA41-400BRG at 80 °C case temperature?

At T_c = 80 °C, the device delivers 40 A RMS with R_th(j-c) = 0.9 °C/W. Assuming T_j(max) = 125 °C, allowable ΔT = 45 °C, yielding P_D = 45 °C ÷ 0.9 °C/W = 50 W. However, datasheet Figure 1 limits P_D to ~36 W at 40 A due to on-state voltage and thermal saturation effects.

Can BTA41-400BRG be used with a microcontroller GPIO without a driver stage?

Yes - with I_GT ≤ 50 mA and V_GT ≤ 1.3 V, many 3.3 V or 5 V microcontrollers can directly drive the gate via a current-limiting resistor (e.g., 68 Ω for 50 mA at 3.3 V). Ensure gate pulse width exceeds 10 µs and dV/dt remains below 500 V/µs during triggering.

Does the insulated tab eliminate the need for thermal interface material?

No - the 2500 V_rms isolation applies only to electrical barrier integrity; thermal interface material (e.g., thermal grease or pad) is still required between the tab and heatsink to minimize R_th(c-hs) and maintain junction temperature within −40 to +125 °C limits.

How does BTA41-400BRG differ from BTA40-600B in practical use?

BTA40-600B uses RD91 package (larger, non-isolated, 20 g weight) with higher thermal mass but requires external insulation. BTA41-400BRG uses lighter (4.5 g), compact TOP3 insulated package enabling simpler mechanical integration and certified isolation - making it preferable for space-constrained, safety-certified designs.