STMicroelectronics BZW06-31BRL

Overview

BZW06-31BRL from STMicroelectronics is a bidirectional transient voltage suppression diode in DO-15 package, designed for IEC 61000-4-2 ESD protection (30 kV air/contact discharge) and IEC 61000-4-4 surge immunity (4 kV level 4). It features 31 V stand-off voltage (VRM), 49.9 V clamping voltage at 12 A (10/1000 µs), and 600 W peak pulse power rating. It is used in AC/DC power inputs and telecom line interfaces requiring robust overvoltage protection at junction temperatures up to 175 °C.

For engineers reviewing the BZW06-31BRL datasheet, BZW06-31BRL pinout, BZW06-31BRL application, or BZW06-31BRL equivalent, this page delivers verified electrical characteristics, DO-15 terminal polarity, real-world clamping behavior under 10/1000 µs and 8/20 µs transients, and validated alternatives for unidirectional/bidirectional TVS selection in industrial power supplies and communication ports.

Technical Context

The BZW06-31BRL implements planar-junction silicon avalanche technology optimized for low leakage (<0.2 µA at VRM = 31 V) and stable clamping performance across -55 °C to +175 °C operating junction temperature. Its bidirectional structure enables symmetrical surge suppression on AC-coupled lines without polarity constraints.

It meets IEC 61000-4-2 level 4 (30 kV contact/air discharge) and IEC 61000-4-4 level 4 (4 kV), with dynamic resistance of 1.01 Ω at 10/1000 µs and 0.427 Ω at 8/20 µs-enabling predictable voltage limiting during fast-rising transients in telecom and SMPS front-end circuits.

Key Specifications

Pinout & Package

DO-15 (JEDEC DO-204AC) package: axial-leaded, epoxy-molded, matte tin-plated leads. Cathode band marking identifies polarity; for bidirectional operation, both terminals are functionally symmetric but marked per standard DO-15 orientation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bidirectional TVS protection applications.

Compared with SMBJ33CA and P6KE33CA, BZW06-31BRL offers lower clamping voltage (49.9 V vs. ≥53.3 V) and superior thermal stability up to 175 °C, making it preferred for high-reliability industrial power and telecom applications where voltage margin and junction temperature headroom are critical.

Availability

BZW06-31BRL is available at Aetrix Electronics and suitable for industrial AC/DC power inputs, telecom line interfaces, SMPS secondary-side outputs, and automotive body control module inputs requiring stable component supply and long-term lifecycle support.

Supply support for BZW06-31BRL 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 microcontrollers, power devices, sensors, and protection components for industrial, automotive, and consumer markets.

The BZW06 series belongs to ST's high-power TVS diode portfolio, engineered specifically for robust transient immunity in harsh electromagnetic environments-targeting AC mains, telecom infrastructure, and industrial power conversion systems.

FAQ

What is the polarity configuration of BZW06-31BRL?

BZW06-31BRL is a bidirectional TVS diode, meaning it provides symmetrical clamping for both positive and negative transients. It has no functional anode or cathode in surge suppression mode-both terminals behave identically under reverse and forward bias during transient events. The physical cathode band marking follows DO-15 convention but does not imply unidirectional operation.

How does BZW06-31BRL perform at elevated temperatures?

At 175 °C junction temperature, BZW06-31BRL maintains full 600 W peak pulse power capability for 10/1000 µs transients, with VBR increasing by +9.9%/°C and VCL scaling linearly per αT = 9.9 × 10⁻⁴/°C. Its leakage remains below 1000 nA at VRM, ensuring stable operation in thermally demanding locations like enclosed power supplies and under-hood ECUs.

Can BZW06-31BRL replace unidirectional TVS diodes in existing designs?

No-BZW06-31BRL is strictly bidirectional and must not be substituted for unidirectional types (e.g., BZW06-31RL) in DC-biased circuits. In such cases, reverse voltage could forward-bias the device and cause excessive leakage or failure. Use only in AC-coupled or floating differential lines where symmetrical clamping is required and DC bias is absent or negligible.

What is the recommended PCB layout for optimal thermal performance?

For best thermal dissipation, mount BZW06-31BRL with ≥1 cm² copper area under each lead on FR4 PCB (70 µm Cu thickness), achieving Rth(j-a) ≈ 3.5 °C/W. Avoid narrow traces; use thermal reliefs only if soldering process requires them. Maintain ≥2 mm clearance from heat sources and ensure axial leads are fully soldered to minimize thermal resistance at the lead-to-pad interface.