STMicroelectronics BTA26-700BRG

Overview

BTA26-700BRG from STMicroelectronics is a 25 A, 700 V RMS insulated TRIAC in TOP3 package, designed for AC mains switching in static relays and phase-control dimmers. It supports standard 4-quadrant triggering (IGT ≤ 50 mA) and delivers high commutation robustness (dI/dt ≥ 13 A/ms, dV/dt ≥ 500 V/µs) with 2500 VRMS insulation rating and RoHS-compliant construction.

For engineers reviewing the BTA26-700BRG datasheet, BTA26-700BRG pinout, BTA26-700BRG application, or BTA26-700BRG equivalent, key selection criteria include RMS current derating at Tc = 100 °C, snubberless vs. standard gate sensitivity (35/50 mA), thermal resistance (Rth(j-c) = 0.9 °C/W), and UL1557 recognition (file 81734).

Technical Context

This insulated TRIAC operates across all four quadrants with gate-triggered turn-on and controlled commutation during AC zero-crossing transitions. Its low dynamic on-state resistance (RD = 16 mΩ) and low threshold voltage (VTO = 0.85 V at 125 °C) minimize conduction losses in high-current AC loads.

Thermal design is enabled by clip-bonded construction yielding Rth(j-c) = 0.9 °C/W and junction-to-ambient Rth(j-a) ≈ 50 °C/W (typ.). The device sustains repetitive surge currents up to 250 A (50 Hz, 20 ms) and non-repetitive fusing I²t = 340 A²s.

Key Specifications

Pinout & Package

Package: TOP3 insulated (plastic housing with electrically isolated tab rated 2500 VRMS). Dimensions: 20.4–21.1 mm length × 15.1–15.5 mm width × 4.4–4.6 mm height (see DS13701 Rev 2, Fig. 11).

Key Features

Applications

Equivalent & Alternatives

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

Compared with BTA26-600BRG and BTB26-700BWRG, the BTA26-700BRG uniquely combines 700 V blocking, 25 A RMS, 2500 VRMS reinforced insulation, and UL1557 recognition-making it the only option qualified for safety-critical, user-accessible 400 VAC applications without supplemental isolation.

Availability

BTA26-700BRG is available at Aetrix Electronics and suitable for heating regulation, light dimming, static relay implementation, and induction motor starting requiring stable component supply across industrial OEM and embedded control programs.

Supply support for BTA26-700BRG 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, specializing in power management, analog, MEMS, and microcontrollers for industrial, automotive, and consumer markets.

The BTA26 series belongs to ST's high-power AC switching portfolio, engineered specifically for robust, insulated TRIAC solutions in mains-connected control systems demanding safety certification and thermal efficiency.

FAQ

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

The BTA26-700BRG supports 25 A RMS conduction at Tc = 100 °C, as specified in Absolute Maximum Ratings (Table 1). Exceeding this temperature requires derating per Figure 2 in DS13701 Rev 2; at Tc = 110 °C, IT(RMS) drops to ~22 A. Heatsink design must maintain case temperature ≤ 100 °C under worst-case ambient and airflow conditions.

Does BTA26-700BRG support snubberless operation?

Yes - BTA26-700BRG supports snubberless (3-quadrant) operation with IGT = 35 mA (CW variant), validated for inductive loads without external RC snubbers. Standard (4-quadrant) mode uses IGT = 50 mA (BW variant). Snubberless operation reduces bill-of-materials count but requires verification of load dI/dt against the device's (dI/dt)c ≥ 13 A/ms specification.

Is the insulated tab rated for 2500 VRMS with DC or AC?

The 2500 VRMS insulation rating (VINS) applies to sinusoidal AC voltage applied for 1 minute between the tab and main terminals, per UL1557 test requirements. It is not rated for equivalent DC voltage; DC testing would require derating per IEC 60664-1. This rating enables use in Class I equipment with basic insulation plus protective earth.

How does the 700 V rating compare to common mains voltages?

The 700 V VDRM/VRRM provides ≥1.7× safety margin over 400 VAC three-phase line-to-line systems (566 V peak) and ≥3× margin over 230 VAC single-phase (325 V peak), accommodating transient surges and long-term voltage drift. It exceeds EN 61000-4-5 Level 4 surge immunity requirements (4 kV line-earth) when properly protected with MOVs.