STMicroelectronics BTB08-800TWRG

Overview

BTB08-800TWRG from STMicroelectronics is a snubberless, logic-level triac rated for 8 A RMS on-state current and 800 V repetitive peak off-state voltage (VDRM/VRRM), designed for AC switching in phase-control and zero-crossing applications. It features 5 mA maximum gate trigger current (IGT), low 1.2 V gate trigger voltage (VGT), and high commutation robustness for inductive loads such as motor starters and heating regulators.

For engineers reviewing the BTB08-800TWRG datasheet, BTB08-800TWRG pinout, BTB08-800TWRG application, or BTB08-800TWRG equivalent, key selection criteria include its snubberless operation, 5 mA logic-level gate drive compatibility, 400 V/µs dV/dt immunity at 125 °C, and TO-220AB package with non-insulated tab for thermal management in compact AC control designs.

Technical Context

This triac operates in three quadrants (I, II, III) and is optimized for snubberless inductive load switching, eliminating external RC snubbers in motor speed controllers and static relays. Its critical rate of rise of off-state voltage (dV/dt) is guaranteed at 400 V/µs at Tj = 125 °C with gate open, and it supports direct interfacing with microcontroller GPIOs due to low 5 mA IGT and 1.2 V VGT.

The device uses a standard silicon-based thyristor structure with enhanced commutation performance enabled by optimized doping and gate geometry. Thermal resistance from junction to case is 1.6 °C/W (TO-220AB), enabling 8 A RMS conduction at Tc = 110 °C without forced cooling in industrial-grade PCB layouts.

Key Specifications

Pinout & Package

BTB08-800TWRG is housed in a non-insulated TO-220AB package with metal tab electrically connected to MT2 (A2). The package provides mechanical stability and thermal dissipation via screw-mount heatsinking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with BTB08-800SWRG, the BTB08-800TWRG offers tighter gate sensitivity for ultra-low-power MCU interfaces; versus T835-800G, it provides through-hole mechanical robustness and simpler thermal mounting-critical for field-serviceable industrial controls.

Availability

BTB08-800TWRG is available at Aetrix Electronics and suitable for motor speed control, heating regulation, static relay replacement, and light dimming requiring stable component supply across industrial OEM and embedded design cycles.

Supply support for BTB08-800TWRG 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, specializing in power management, analog, MEMS, and microcontroller technologies for industrial, automotive, and consumer markets.

BTB08-800TWRG belongs to ST's high-reliability snubberless triac product line, engineered specifically for robust AC power control in inductive and resistive loads where reduced system complexity and long-term reliability are critical.

FAQ

What is the maximum junction temperature for continuous operation?

The BTB08-800TWRG has an operating junction temperature range of –40 °C to +125 °C. Continuous conduction at 8 A RMS requires case temperature ≤110 °C, enforced by thermal design using the 1.6 °C/W junction-to-case resistance and appropriate heatsinking per Figure 2 in DS2114.

Does this triac require a heatsink in all applications?

Yes - at 8 A RMS full-sine conduction, thermal dissipation exceeds 2 W. Without a heatsink, junction temperature will exceed 125 °C even at ambient 25 °C. A minimum 10 cm² aluminum heatsink is recommended for natural convection; forced airflow reduces required surface area proportionally per Figure 3.

Can BTB08-800TWRG be used in zero-crossing switch applications?

Yes - its three-quadrant triggering and low IGT make it compatible with zero-crossing driver ICs (e.g., MOC3063) and microcontroller-based zero-crossing detection circuits. However, it does not integrate zero-crossing logic; external timing circuitry is required to gate-trigger near voltage zero.

Is the TO-220AB tab electrically isolated?

No - the metal tab is internally connected to A2 (MT2) and is not insulated. This requires careful PCB layout to avoid shorting A2 to ground or chassis. For insulated mounting, ST's BTA08-800TWRG variant (TO-220AB Ins.) provides 2500 VRMS isolation between tab and A2.