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STMicroelectronics BZW50-120B
- Part No.:
- BZW50-120B
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- R-6, Axial
- Datasheet:
-
BZW50-120B.pdf
- Description:
- TVS DIODE 120VWM 274VC R6
- Quantity:
- Payment:
- Shipping:
Inventory:606
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Product details
Overview
BZW50-120B 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 215 V (max) under 23 A surge, and operates up to 175 °C junction temperature-enabling robust protection in industrial motor drives, telecom power supplies, and outdoor PoE equipment.
For engineers reviewing the BZW50-120B datasheet, BZW50-120B pinout, BZW50-120B application, or BZW50-120B equivalent, key selection criteria include its 120 V stand-off voltage, bidirectional polarity, low dynamic resistance (2.96 Ω), IEC 61000-4-2 ±30 kV ESD immunity, and R6 axial package compatibility with high-power PCB layouts.
Technical Context
The BZW50-120B uses planar silicon junction technology optimized for low leakage (<5 µA at 120 V) and stable clamping over temperature (αT = 10.8 × 10−4/°C). Its bidirectional structure enables symmetrical surge suppression on AC-coupled or floating lines without polarity constraints.
It supports dual-pulse standards: IEC 61000-4-4 level 4 (4 kV ring wave) and IEC 61000-4-2 (±30 kV contact/air discharge), with verified clamping performance up to 274 A (8/20 µs) and thermal stability across −55 °C to +175 °C operating range.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Stand-off Voltage (VRM) | 120 V - Maximum continuous reverse working voltage before conduction begins |
| Breakdown Voltage (VBR) | 133 V min at 1 mA - Confirmed avalanche onset threshold ensuring precise trigger margin |
| Clamping Voltage (VCL) | 215 V max at 23 A (10/1000 µs) - Limits downstream voltage stress during surge events |
| Peak Pulse Power (PPP) | 5000 W (10/1000 µs) - Sustains high-energy transients common in industrial power rails |
| Dynamic Resistance (RD) | 2.96 Ω - Low impedance ensures rapid voltage stabilization during fast surges |
| Junction Temperature Range | −55 °C to +175 °C - Enables deployment in under-hood automotive, solar inverters, and factory-floor controllers |
| Leakage Current (IRM) | ≤5 µA at 120 V - Minimizes standby power loss in always-on systems |
Pinout & Package
The BZW50-120B is housed in an R6 axial leaded package (DO-201AD), with two terminals: anode and cathode marked by a cathode band on unidirectional variants; bidirectional versions (denoted by "B") have no polarity marking and symmetric terminal behavior.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Surge current entry point (bidirectional) | Accepts transient energy from either direction; no fixed polarity reference required |
| Cathode | Surge current return path (bidirectional) | Completes low-impedance path to ground or reference rail during both positive and negative surges |
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 operation | 175 °C max junction temperature - Supports placement near heat-generating components without derating |
| Low dynamic resistance | 2.96 Ω - Reduces clamping overshoot and improves protection margin for 24–48 V systems |
| UL 497B certification | QVGQ2.E136224 - Validates suitability for telecom and data line surge protection per safety standards |
| ECOPACK® compliance | Lead-free matte tin plating - Ensures RoHS/REACH compliance and solderability reliability |
Applications
| Industrial Motor Drives | Telecom Power Supplies |
|---|---|
Use Scenario: Protection of DC bus inputs against load dump and inductive kickback in servo amplifier modules. IC Role / Device Role / Timing Role: Bidirectional TVS clamp absorbing 5000 W surges while maintaining <215 V rail excursion. Use Value: Prevents MOSFET gate oxide failure and controller IC latch-up during field-replaceable module hot-swap events. | Use Scenario: Surge suppression on −48 V DC distribution lines feeding base station RF amplifiers. IC Role / Device Role / Timing Role: Fast-response voltage limiter meeting IEC 61000-4-5 level 4 (4 kV) requirements. Use Value: Maintains uninterrupted operation during lightning-induced surges on outdoor cabinet power feeds. |
| PoE-Powered Devices | Solar Inverter DC Inputs |
Use Scenario: Input-side protection of IEEE 802.3bt Type 4 (90 W) powered devices against cable discharge events. IC Role / Device Role / Timing Role: Bidirectional clamping element on PSE/PD interface with ≤5 µA leakage at 57 V nominal. Use Value: Preserves Class 8 power negotiation integrity while surviving repeated ±30 kV ESD strikes. | Use Scenario: String-level overvoltage protection in residential photovoltaic combiner boxes exposed to grid switching transients. IC Role / Device Role / Timing Role: Standoff-rated (120 V) TVS absorbing 274 A (8/20 µs) surges from nearby lightning strikes. Use Value: Extends MPPT controller lifetime by limiting input voltage to <215 V during worst-case surge conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar bidirectional TVS protection applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ120CA | Lower peak power (600 W), smaller SMB package, higher clamping (200 V @ 12.5 A) | Limited to lower-energy surges; unsuitable for 5 kW system-level testing | Select when board space is constrained and surge energy stays below 1 kW (10/1000 µs) |
| 1.5KE120CA | Higher leakage (50 µA), TO-218 package, same 120 V standoff but 230 V clamping @ 21.7 A | Less precise clamping margin; requires larger heatsinking due to lower thermal efficiency | Choose only if legacy footprint compatibility is mandatory and thermal management is prioritized over clamping accuracy |
Compared with SMBJ120CA and 1.5KE120CA, BZW50-120B provides 8.3× higher peak power handling, tighter clamping tolerance (215 V vs. ≥230 V), and superior high-temperature stability-making it the preferred choice for mission-critical 48–120 V DC systems requiring certified 5 kW surge resilience.
Availability
BZW50-120B is available at Aetrix Electronics and suitable for industrial motor drives, telecom power supplies, PoE-powered devices, and solar inverter DC inputs requiring stable component supply across extended product lifecycles.
Supply support for BZW50-120B 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 portfolio, engineered specifically for system-level surge immunity in harsh-environment power conversion and communication infrastructure where reliability under repetitive 5 kW transients is non-negotiable.
FAQ
What is the maximum surge current the BZW50-120B can handle?
The BZW50-120B sustains 23 A (10/1000 µs) with clamping voltage ≤215 V, and up to 274 A under 8/20 µs waveform (per Table 2). Its 60 kW capability at 8/20 µs reflects short-duration energy absorption-not steady-state rating-and must be applied within thermal limits defined in Figure 3.
Is the BZW50-120B compatible with lead-free reflow processes?
Yes. The device features matte tin-plated leads qualified per J-STD-002 and JESD 22-B102 E3, and supports ST's recommended reflow profile peaking at 240–245 °C for 60 seconds (Figure 20), fully compliant with IPC/JEDEC J-STD-020 Class 3 moisture sensitivity level.
How does bidirectional operation affect circuit layout?
Unlike unidirectional TVS diodes, BZW50-120B has no polarity marking and conducts identically in both directions-eliminating orientation errors during placement. Layout requires symmetric trace routing and equal copper area under both leads (per Figure 12) to maintain thermal balance and avoid localized heating.
Does the BZW50-120B meet UL 497B for telecom surge protection?
Yes. It carries UL 497B file number QVGQ2.E136224, certifying compliance for use in primary and secondary telecom circuits-including DSL, T1/E1, and PoE interfaces-where isolation, voltage withstand, and surge current handling are validated per ANSI/UL 497B Annex D.
BZW50-120B 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):
- 120V
- Voltage - Breakdown (Min):
- 133V
- Voltage - Clamping (Max) @ Ipp:
- 274V
- Current - Peak Pulse (10/1000µs):
- 219A (8/20µs)
- Power - Peak Pulse:
- 5000W (5kW)
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- 950pF @ 1MHz
- Operating Temperature:
- -
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- R-6
BZW50-120B FAQ
1.How can I place an order for BZW50-120B through Aetrix?
Please submit a Request for Quotation (RFQ) for BZW50-120B 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 BZW50-120B reliable?
The price and inventory of BZW50-120B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZW50-120B is usually 5 days.
3.What payment methods are accepted for BZW50-120B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZW50-120B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZW50-120B?
BZW50-120B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZW50-120B 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 BZW50-120B?
For technical support, including BZW50-120B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZW50-120B requirements.
6.How does Aetrix verify that BZW50-120B is sourced from the original manufacturer or authorized distributors?
All BZW50-120B 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 BZW50-120B meets industry standards.
7.What is the process for return or replacement of BZW50-120B?
All BZW50-120B units undergo pre-shipment inspection (PSI). If there is an issue with BZW50-120B, 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 BZW50-120B part is unused and in its original packaging.
Return procedure for BZW50-120B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZW50-120B Tags
-
ESD9B5.0ST5G
onsemi
-
DESD3V3E1BL-7B
Diodes Incorporated
-
ESD5Z3.3T1G
onsemi
-
D5V0H1B2LP-7B
Diodes Incorporated
-
D5V0P1B2LP-7B
Diodes Incorporated
-
DESD5V0U1BA-7
Diodes Incorporated
-
ESD5Z5.0T1G
onsemi
-
DESD5V0U1BB-7
Diodes Incorporated
-
D12V0L1B2LP-7B
Diodes Incorporated
-
PESD2V0Y1BSFYL
Nexperia USA Inc.
-
DF2S5M4CT,L3F
Toshiba Semiconductor and Storage
-
D5V0L1B2WS-7
Diodes Incorporated
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