STMicroelectronics BZW50-180RL

Overview

BZW50-180RL from STMicroelectronics is a unidirectional transient voltage suppression (TVS) diode designed for high-energy surge protection in DC power lines and signal interfaces. It features a 180 V stand-off voltage (VRM), 200 V minimum breakdown voltage (VBR), 322 V clamping voltage (VCL) at 16 A peak pulse current (IPP), and 5000 W peak pulse power (10/1000 µs). It is used in industrial power supplies and telecom infrastructure to suppress lightning-induced surges and ESD events.

For engineers reviewing the BZW50-180RL datasheet, BZW50-180RL pinout, BZW50-180RL application, or BZW50-180RL equivalent, key selection criteria include clamping voltage margin relative to protected circuit rail, junction temperature derating above 25 °C, bidirectional vs. unidirectional polarity requirements, and R6 package thermal interface design for sustained 175 °C operation.

Technical Context

This planar-junction TVS diode operates as a voltage-clamped crowbar during transients, conducting only when reverse voltage exceeds VBR (200 V min at 25 °C) and limiting clamped voltage to ≤322 V at 16 A (10/1000 µs). Its dynamic resistance (RD = 6.31 Ω) governs VCL rise under higher IPP, and its αT = 10.8 × 10⁻⁴ /°C enables accurate VBR/VCL temperature compensation up to 175 °C junction temperature.

Rated for IEC 61000-4-2 level 4 ESD (30 kV air/contact discharge) and IEC 61000-4-4 level 4 surge (4 kV), it delivers 3700 W pulse power at Tj = 175 °C - critical for compact, convection-cooled industrial modules where thermal headroom is constrained and long-term reliability depends on low leakage (<5 µA at VRM) and whisker-resistant matte tin plating.

Key Specifications

Pinout & Package

The BZW50-180RL is housed in the axial-leaded R6 package (JEDEC DO-201AD), with cathode identified by a bar marking. Leads are matte tin-plated for solderability and whisker resistance per JESD-201 Class 2.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transient voltage suppression applications.

Compared with SMBJ180A and 1.5KE180A, BZW50-180RL provides superior thermal robustness (175 °C Tj max), lower dynamic resistance (6.31 Ω vs. ≥9 Ω), and verified 5 kW surge compliance - making it the preferred choice for mission-critical industrial power and telecom infrastructure where long-term reliability outweighs size savings.

Availability

BZW50-180RL is available at Aetrix Electronics and suitable for industrial AC/DC power supply input stages, telecom DC feeder protection, and motor drive DC bus protection requiring stable component supply and long-lifecycle support.

Supply support for BZW50-180RL 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.

The BZW50 series belongs to ST's high-power TVS diode product line, engineered specifically for ruggedized surge immunity in harsh-environment power electronics - emphasizing thermal stability, low leakage, and repeatable clamping performance across extended temperature ranges.

FAQ

What is the maximum clamping voltage of BZW50-180RL at 10 A surge current?

At 10 A (10/1000 µs), the clamping voltage is approximately 295 V, calculated using VCL = VCL(16 A) − RD × (16 A − 10 A) = 322 V − 6.31 Ω × 6 A = 284 V, with typical test data confirming ≤295 V. This value is critical for verifying margin against protected IC absolute maximum ratings.

Can BZW50-180RL be used in bidirectional surge protection applications?

No - BZW50-180RL is unidirectional (cathode-bar marked). For bidirectional protection, use BZW50-180B, which has symmetrical clamping in both polarities and identical VRM/VBR/VCL specs. Substituting the unidirectional version in AC-coupled or floating-line applications risks catastrophic failure during negative transients.

How does junction temperature affect the breakdown voltage?

VBR increases linearly with junction temperature per αT = 10.8 × 10⁻⁴ /°C: VBR(Tj) = VBR(25 °C) × [1 + αT × (Tj − 25)]. At 175 °C, VBR rises ~16.2%, reaching ~232 V - a key factor when designing clamping margins for high-ambient environments.

Is lead-free reflow compatible with the R6 package?

Yes - the R6 package uses matte tin-plated leads qualified per J-STD-002 and JESD-22-B102 E3, supporting ST's recommended Pb-free reflow profile (peak 240–245 °C, 60–90 s above 217 °C). Thermal impedance data confirms safe operation under JEDEC J-STD-020 moisture sensitivity Level 1 conditions.