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STMicroelectronics BZW50-12B
- Part No.:
- BZW50-12B
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- R-6, Axial
- Datasheet:
-
BZW50-12B.pdf
- Description:
- TVS DIODE 12VWM 28VC R6
- Quantity:
- Payment:
- Shipping:
Inventory:349
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Product details
Overview
BZW50-12B from STMicroelectronics is a bidirectional transient voltage suppression (TVS) diode designed for high-energy surge protection in DC power lines and signal interfaces. It delivers 5000 W peak pulse power (10/1000 µs), clamps at 22 V (max) under 227 A surge, and operates up to 175 °C junction temperature - enabling robust protection in industrial power supplies, telecom infrastructure, and automotive ECUs.
For engineers reviewing the BZW50-12B datasheet, BZW50-12B pinout, BZW50-12B application, or BZW50-12B equivalent, this device is selected for its verified 12 V stand-off voltage, low dynamic resistance (0.032 Ω), bidirectional polarity, IEC 61000-4-2 ±30 kV ESD immunity, and R6 axial package compatibility with high-reliability PCB layouts.
Technical Context
The BZW50-12B uses planar silicon junction technology optimized for low leakage (<5 µA at 12 V) and stable clamping across -55 °C to +175 °C operating range. Its bidirectional structure provides symmetrical surge suppression without polarity dependency, supporting both positive and negative transients on the same line.
It meets IEC 61000-4-4 Level 4 (4 kV) and exceeds IEC 61000-4-2 Level 4 for ESD (±30 kV air/contact discharge). The 0.032 Ω dynamic resistance ensures minimal voltage overshoot during fast 8/20 µs surges up to 2143 A, while thermal impedance remains stable under repeated pulse stress.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 12 V - Maximum continuous reverse working voltage before clamping initiates |
| Breakdown Voltage (VBR) | 13.3 V min - Voltage at which device enters avalanche conduction under 1 mA test current |
| Clamping Voltage (VCL) | 22 V max at 227 A (10/1000 µs) - Peak voltage seen by protected circuit during rated surge |
| Peak Pulse Power (PPP) | 5000 W (10/1000 µs) - Sustained surge energy handling capability at 25 °C ambient |
| Leakage Current (IRM) | ≤5 µA at VRM - Ensures minimal standby power loss and signal integrity in high-impedance circuits |
| Dynamic Resistance (RD) | 0.032 Ω - Low impedance limits voltage overshoot during fast-rising transients |
| Junction Temperature Range | -55 °C to +175 °C - Enables operation in under-hood automotive and industrial environments |
Pinout & Package
The BZW50-12B is housed in an R6 axial leaded package (DO-201AD), with two terminals: anode and cathode marked by a cathode band on unidirectional variants; the "B" suffix denotes bidirectional symmetry - no polarity marking required. Leads are matte tin-plated per J-STD-002 and MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode (symmetrical) | Surge current path | Both terminals function identically - bidirectional conduction enables single-device protection of AC or floating DC lines |
Key Features
| Feature | Design Value |
|---|---|
| IEC 61000-4-2 ESD immunity | ±30 kV contact/air discharge - eliminates need for external ESD staging in front-end interfaces |
| High-temperature reliability | Rated for 175 °C junction operation - supports compact thermal design in sealed enclosures |
| Low dynamic resistance | 0.032 Ω - reduces clamping voltage rise during fast 8/20 µs surges, improving downstream IC survivability |
| UL 497B certification | QVGQ2.E136224 - validates suitability for telecom and industrial surge protection per UL safety standards |
| ECOPACK® compliance | Meets RoHS and halogen-free requirements - supports environmental compliance in global OEM programs |
Applications
| Industrial Power Supply Protection | Automotive Body Control Module (BCM) |
|---|---|
Use Scenario: Protecting 12 V DC input rails in programmable logic controllers (PLCs) against load dump and inductive switching transients. IC Role / Device Role: Primary overvoltage clamp placed upstream of DC-DC converters and microcontrollers. Use Value: Clamps to ≤22 V during 227 A surges, preventing latch-up or burnout in downstream 3.3 V/5 V logic. |
Use Scenario: Safeguarding LIN bus and sensor supply lines in BCMs exposed to battery reversal and jump-start events. IC Role / Device Role: Bidirectional transient suppressor on 12 V sensor VCC and LIN signal lines. Use Value: Symmetrical clamping ensures protection regardless of transient polarity, meeting ISO 7637-2 Pulse 1/2a/5a requirements. |
| Telecom Base Station DC Feeds | Renewable Energy Inverter Control Boards |
Use Scenario: Shielding remote radio head (RRH) power inputs from lightning-induced surges on outdoor copper feeds. IC Role / Device Role: First-stage TVS on -48 V DC input before DC-DC isolation and monitoring circuitry. Use Value: Withstands 4 kV IEC 61000-4-4 Level 4 surges and maintains <5 µA leakage at full -48 V reverse bias. |
Use Scenario: Protecting gate driver supply rails in solar inverter half-bridges from cross-conduction-induced voltage spikes. IC Role / Device Role: Localized clamping on isolated 15 V gate drive supplies feeding SiC MOSFETs. Use Value: 175 °C rating allows placement near heat-generating power stages without derating. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ12CA | Lower PPP (600 W), SMA package, higher VCL (22.5 V @ 27.1 A) | Targeted for lower-energy consumer electronics; not rated for 5 kA 8/20 µs surges | Select when board space is constrained and surge threat level is limited to IEC 61000-4-2 only |
| P6KE12CA | Same R6 package but lower PPP (600 W), higher VCL (22.5 V @ 27.1 A), older DO-15 construction | Limited to legacy designs; lacks IEC 61000-4-4 Level 4 validation and 175 °C rating | Use only for cost-sensitive replacements where 5 kA surge immunity is not required |
Compared with SMBJ12CA and P6KE12CA, the BZW50-12B delivers 8.3× higher peak pulse power, validated 4 kV IEC 61000-4-4 immunity, and extended 175 °C operation - making it uniquely suited for industrial and automotive power rail protection where sustained surge energy and thermal margin are critical.
Availability
BZW50-12B is available at Aetrix Electronics and suitable for industrial power supply protection, automotive body control modules, telecom base station DC feeds, and renewable energy inverter control boards requiring stable component supply and long-term lifecycle support.
Supply support for BZW50-12B 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 robust, high-energy transient suppression in harsh-environment applications where reliability under thermal and electrical stress is non-negotiable.
FAQ
What is the maximum surge current the BZW50-12B can handle?
The BZW50-12B sustains 227 A under the standard 10/1000 µs waveform and up to 2143 A under the 8/20 µs waveform - verified per IEC 61000-4-4 testing. Its 5000 W peak pulse power rating reflects performance at 25 °C; derating applies above 25 °C ambient per Figure 3 in DS0662.
Is the BZW50-12B compatible with lead-free reflow soldering?
Yes - the BZW50-12B is qualified for lead-free reflow per ST's recommended profile (peak 240–245 °C, 60–90 s above 217 °C), compliant with IPC/JEDEC J-STD-020. Its matte tin-plated leads meet JESD 22-B102 E3 and MIL-STD-750 Method 2026 for solderability and whisker resistance.
How does bidirectional operation affect circuit layout?
Because the BZW50-12B is bidirectional, it has no anode/cathode orientation - either terminal connects to the line being protected, and the other to ground or reference. This simplifies layout on AC-coupled or floating DC lines and eliminates polarity-checking during assembly.
Does the BZW50-12B require a heatsink for 5000 W surge handling?
No - the 5000 W rating applies to single-pulse conditions with no heatsink. Thermal impedance data (Figure 11) shows junction-to-ambient resistance drops significantly with copper area; for repetitive surges, PCB copper pour under both leads is recommended, but no external heatsink is needed for compliance with IEC 61000-4-4 or ISO 7637-2.
BZW50-12B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- R-6, Axial
- Series:
- BZW50, TRANSIL™
- Packaging:
- Cut Tape (CT)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 12V
- Voltage - Breakdown (Min):
- 13.3V
- Voltage - Clamping (Max) @ Ipp:
- 28V
- Current - Peak Pulse (10/1000µs):
- 2143A (2.143kA) (8/20µs)
- Power - Peak Pulse:
- 5000W (5kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 9250pF @ 1MHz
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- R-6
BZW50-12B FAQ
1.How can I place an order for BZW50-12B through Aetrix?
Please submit a Request for Quotation (RFQ) for BZW50-12B on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for BZW50-12B reliable?
The price and inventory of BZW50-12B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZW50-12B is usually 5 days.
3.What payment methods are accepted for BZW50-12B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZW50-12B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZW50-12B?
BZW50-12B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZW50-12B order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for BZW50-12B?
For technical support, including BZW50-12B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZW50-12B requirements.
6.How does Aetrix verify that BZW50-12B is sourced from the original manufacturer or authorized distributors?
All BZW50-12B products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BZW50-12B meets industry standards.
7.What is the process for return or replacement of BZW50-12B?
All BZW50-12B units undergo pre-shipment inspection (PSI). If there is an issue with BZW50-12B, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The BZW50-12B part is unused and in its original packaging.
Return procedure for BZW50-12B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZW50-12B Tags
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DESD3V3E1BL-7B
Diodes Incorporated
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Diodes Incorporated
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Diodes Incorporated
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Nexperia USA Inc.
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Toshiba Semiconductor and Storage
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Diodes Incorporated
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