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Taiwan Semiconductor Corporation BZW04-256B
- Part No.:
- BZW04-256B
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
BZW04-256B.pdf
- Description:
- TVS DIODE 256VWM 414VC DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:2,730
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Product details
Overview
BZW04-256B from Taiwan Semiconductor is a unidirectional transient voltage suppressor (TVS) diode designed for high-energy surge protection in DC power lines and signal interfaces. It features a 256 V working stand-off voltage (VWM), 285–315 V breakdown voltage (VBR) at 1 mA, 400 W peak pulse power (PPK) at 10/1000 μs, clamping voltage of 414 V at 1 A peak impulse current, and operates across –55 °C to +175 °C junction temperature range - deployed in automotive lighting control modules and industrial PLC I/O protection.
For engineers reviewing the BZW04-256B datasheet, BZW04-256B pinout, BZW04-256B application, or BZW04-256B equivalent, key selection criteria include verified unidirectional polarity, DO-204AL (DO-41) package compatibility, clamping performance under 10/1000 μs transients, thermal resistance (RθJL = 60 °C/W), and AEC-Q101 qualification status for automotive-grade reliability.
Technical Context
The BZW04-256B functions as a silicon avalanche diode with fast response time (<1 ns) and low dynamic impedance during surge events. Its unidirectional configuration provides reverse-biased clamping only, requiring correct anode/cathode orientation in series with protected circuitry.
It delivers 400 W peak pulse power per 10/1000 μs waveform, derates linearly above 25 °C ambient, and maintains <1 μA reverse leakage at 256 V - enabling stable operation in high-impedance sensing paths and battery-backed systems where standby current matters.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 256 V - maximum continuous DC or RMS voltage the device blocks without clamping |
| VBR @ IT=1 mA | 285–315 V - guaranteed avalanche initiation range, defining minimum overvoltage threshold before conduction |
| VC @ IPP=1 A | 414 V - maximum voltage seen across terminals during 1 A surge, limiting stress on downstream ICs |
| PPK | 400 W - peak transient energy absorption capability at 10/1000 μs waveform, critical for ISO 7637-2 pulse 5a compliance |
| RθJL | 60 °C/W - junction-to-lead thermal resistance, enabling reliable heat transfer to PCB copper when mounted per JEDEC standards |
| TJ Range | –55 °C to +175 °C - extended operating temperature support for under-hood automotive and industrial motor drive environments |
Pinout & Package
Package: DO-204AL (DO-41), axial leaded, epoxy-molded case with cathode band marking for unidirectional polarity. Leads are pure tin-plated, solderable per J-STD-002, and meet JESD 201 Class 2 whisker resistance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode (unmarked end) | Input/Line side connection | Connected to source of transient threat (e.g., battery rail or signal line); conducts during reverse surge |
| Cathode (banded end) | Clamp reference / ground side | Connected to system ground or low-impedance return path; defines clamping voltage relative to this node |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified | Validated for automotive applications including engine control units and body electronics per stress test requirements |
| 400 W surge rating (10/1000 μs) | Withstands high-energy load dump and inductive switching transients common in 24 V vehicle systems |
| Clamping voltage ≤414 V @ 1 A | Ensures protected ICs (e.g., CAN transceivers, microcontrollers) remain below absolute maximum ratings during surge |
| Reverse leakage <1 μA @ 256 V | Minimizes quiescent power loss in always-on circuits such as telematics backup supplies |
Applications
| Automotive Lighting Control | Industrial PLC Digital I/O |
|---|---|
Use Scenario: Protecting LED driver ICs and MOSFET gate drivers from load-dump transients in headlamp and foglamp modules. IC Role / Device Role: Primary overvoltage clamp placed between battery rail and driver input stage. Use Value: Prevents latch-up or permanent damage to 30 V-rated logic-level MOSFETs during 12 V system load dump events up to 35 V. | Use Scenario: Safeguarding 24 V digital input channels against EFT bursts and relay coil flyback in programmable logic controllers. IC Role / Device Role: Front-end transient suppression before optocoupler or Schmitt-trigger input conditioning. Use Value: Maintains signal integrity by limiting input voltage to ≤414 V during 4 kV/5 kHz EFT (IEC 61000-4-4) exposure. |
| DC Power Rail Protection | Telecom Power Supply Input |
Use Scenario: Clamping surges on 24 V/48 V DC distribution buses feeding remote sensors and actuators. IC Role / Device Role: Standoff-rated TVS in parallel with bulk capacitance to absorb repetitive switching noise. Use Value: Enables >100,000 surge cycles without degradation due to low dynamic impedance and robust silicon junction design. | Use Scenario: Input-stage protection for AC/DC power supplies in outdoor telecom cabinets exposed to lightning-induced surges. IC Role / Device Role: First-line defense upstream of bridge rectifier and primary-side controller. Use Value: Complies with IEC 61000-4-5 Level 3 (1 kV line-earth) with minimal board space using axial DO-41 footprint. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ250A | Surface-mount SMB package (vs. axial DO-41); same 250 V VWM, but 400 W PPK at 10/1000 μs; slightly higher VC (400 V @ 1 A) | Requires PCB re-layout; better suited for high-density automated assembly | Select when SMT process flow is mandatory and thermal pad layout supports RθJA ≤ 100 °C/W |
| P6KE250A | Legacy through-hole DO-15 package; identical VWM/VBR specs, but lower PPK (600 W at 10/1000 μs); larger footprint and higher RθJL (75 °C/W) | Compatible with legacy socketed designs; less thermally efficient under sustained surge duty | Select for backward compatibility in existing DO-15 footprints where 600 W margin is required |
Compared with SMBJ250A and P6KE250A, the BZW04-256B offers optimal balance of axial leaded manufacturability, AEC-Q101 qualification, and thermal performance (RθJL = 60 °C/W) - making it preferred for new automotive and industrial designs requiring proven reliability without SMT conversion.
Availability
BZW04-256B is available at Aetrix Electronics and suitable for automotive lighting control, industrial PLC digital I/O, and DC power rail protection requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.
Supply support for BZW04-256B 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
Taiwan Semiconductor Corporation (TSC) is a vertically integrated semiconductor manufacturer specializing in discrete power devices, TVS diodes, and rectifiers - headquartered in Hsinchu, Taiwan, with global distribution and AEC-Q101 validation capabilities.
The BZW04 series was developed specifically for high-reliability transient suppression in automotive and industrial environments, emphasizing robust surge handling, extended temperature operation, and RoHS/halogen-free compliance.
FAQ
Is BZW04-256B unidirectional or bidirectional?
The BZW04-256B is a unidirectional TVS diode, indicated by its single cathode band marking and specification table listing only unidirectional parameters (e.g., VBR min/max at 1 mA, no bidirectional VBR row). It clamps only during reverse-voltage transients and must be oriented with cathode toward the protected circuit's ground reference. Bidirectional variants like BZW04-256BB are separate orderable parts.
What is the maximum clamping voltage of BZW04-256B at rated surge current?
The BZW04-256B has a maximum clamping voltage (VC) of 414 V when subjected to a 1 A peak impulse current (IPP) under the standard 10/1000 μs waveform. This value is measured at TA = 25 °C and defines the upper voltage limit imposed on protected circuitry during surge events - critical for ensuring downstream ICs remain within their absolute maximum ratings.
Does BZW04-256B meet AEC-Q101 requirements?
Yes, BZW04-256B is AEC-Q101 qualified, as confirmed in the official Taiwan Semiconductor datasheet (Version J2104) under FEATURES and ORDERING INFORMATION sections. The "H" suffix in alternate ordering codes (e.g., BZW04-256BH) explicitly denotes AEC-Q101 qualification, and BZW04-256B is listed in the same qualified family matrix with full stress test compliance documentation.
What is the thermal resistance from junction to lead (RθJL) for BZW04-256B?
The junction-to-lead thermal resistance (RθJL) of BZW04-256B is 60 °C/W, as specified in the THERMAL PERFORMANCE section of the datasheet. This parameter reflects heat transfer efficiency from the silicon die to the leads under standard mounting conditions (5 × 5 mm copper pads per terminal), directly impacting safe surge repetition rate and steady-state power dissipation limits.
Can BZW04-256B replace P6KE250A in existing designs?
BZW04-256B is not a direct drop-in replacement for P6KE250A due to differences in package outline (DO-41 vs. DO-15), lead spacing, and thermal resistance (60 vs. 75 °C/W). While both share similar VWM (256 V vs. 250 V) and PPK (400 W vs. 600 W), PCB layout changes and thermal validation are required. Use BZW04-256B only after verifying mechanical fit and surge duty cycle compatibility in the target application.
BZW04-256B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Taiwan Semiconductor Corporation
- Package/Case:
- DO-204AL, DO-41, Axial
- Series:
- BZW04
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- -
- Bidirectional Channels:
- 1
- Voltage - Reverse Standoff (Typ):
- 256V
- Voltage - Breakdown (Min):
- 285V
- Voltage - Clamping (Max) @ Ipp:
- 414V
- Current - Peak Pulse (10/1000µs):
- 1A
- Power - Peak Pulse:
- 400W
- Power Line Protection:
- No
- Applications:
- General Purpose
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AL (DO-41)
BZW04-256B FAQ
1.How can I place an order for BZW04-256B through Aetrix?
Please submit a Request for Quotation (RFQ) for BZW04-256B 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 BZW04-256B reliable?
The price and inventory of BZW04-256B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZW04-256B is usually 5 days.
3.What payment methods are accepted for BZW04-256B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZW04-256B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZW04-256B?
BZW04-256B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZW04-256B 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 BZW04-256B?
For technical support, including BZW04-256B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZW04-256B requirements.
6.How does Aetrix verify that BZW04-256B is sourced from the original manufacturer or authorized distributors?
All BZW04-256B 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 BZW04-256B meets industry standards.
7.What is the process for return or replacement of BZW04-256B?
All BZW04-256B units undergo pre-shipment inspection (PSI). If there is an issue with BZW04-256B, 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 BZW04-256B part is unused and in its original packaging.
Return procedure for BZW04-256B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZW04-256B Tags
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