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Taiwan Semiconductor Corporation BZW04-85B
- Part No.:
- BZW04-85B
- Manufacturer:
- Taiwan Semiconductor Corporation
- Category:
- TVS Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
BZW04-85B.pdf
- Description:
- TVS DIODE 85.5VWM 137VC DO204AL
- Quantity:
- Payment:
- Shipping:
Inventory:8,084
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Product details
Overview
BZW04-85B from Taiwan Semiconductor is a bidirectional transient voltage suppressor (TVS) diode in DO-204AL (DO-41) package, designed for high-energy surge clamping in automotive and industrial power rails. It features a 85.5 V working stand-off voltage (VWM), 95–105 V breakdown voltage (VBR) at 1 mA, 400 W peak pulse power (10/1000 μs), 2.9 A maximum peak impulse current (IPP), and 137 V maximum clamping voltage (VC) - enabling robust protection of 24 V/48 V DC systems against EFT and inductive switching transients.
For engineers reviewing the BZW04-85B datasheet, BZW04-85B pinout, BZW04-85B application, or BZW04-85B equivalent, this page delivers verified electrical parameters, thermal performance data (RθJA = 100 °C/W), polarity marking guidance, AEC-Q101 qualification status, and real-world use context for circuit-level transient immunity design.
Technical Context
The BZW04-85B operates as a silicon avalanche diode with bidirectional clamping symmetry, optimized for unidirectional or bidirectional surge suppression without external polarity constraints. Its low dynamic impedance ensures stable clamping under fast-rising transients (typical response time < 1 ns), while the 0.106 %/°C VBR temperature coefficient supports predictable voltage drift across –55 °C to +175 °C junction operation.
Rated for 400 W non-repetitive peak pulse power per 10/1000 μs waveform and 1 W steady-state dissipation at TL = 75 °C, it relies on DO-41 lead-frame thermal conduction (RθJL = 60 °C/W) and meets JESD201 Class 2 whisker resistance and UL 94V-0 flammability requirements - confirming suitability for under-hood automotive modules and industrial PLC I/O stages.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VWM | 85.5 V - Maximum continuous reverse operating voltage before clamping initiates; defines safe DC rail margin for 24 V/48 V systems. |
| VBR @ IT=1 mA | 95–105 V - Breakdown voltage range at 1 mA test current; ensures consistent avalanche turn-on across production lots. |
| VC @ IPP=2.9 A | 137 V - Clamped voltage during 2.9 A 10/1000 μs surge; determines protected IC's maximum transient stress level. |
| PPK | 400 W - Peak pulse power rating at TA = 25 °C; validates capability to absorb ISO 7637-2 Pulse 1/2a/5a energy without failure. |
| TJ max | +175 °C - Maximum junction temperature; enables placement near heat sources in engine control units or motor drives. |
| RθJA | 100 °C/W - Junction-to-ambient thermal resistance on PCB with 10 mm leads; informs heatsinking requirements for repeated surge duty. |
| ID @ VWM | 1 μA - Reverse leakage at 85.5 V; negligible loading on high-impedance sensor or communication lines. |
Pinout & Package
Package: DO-204AL (DO-41), axial-leaded, epoxy-molded case with pure tin-plated leads solderable per J-STD-002. Polarity marked by cathode band for unidirectional variants; BZW04-85B is bidirectional and has no polarity marking - both terminals are functionally identical.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode / Cathode (symmetrical) | Transient current path | Both terminals conduct identically during positive or negative surges; no orientation required during PCB placement. |
| Leads (anode & cathode) | Thermal and electrical interface | Provide mechanical mounting and primary heat conduction path; RθJL = 60 °C/W confirms effective lead-frame cooling. |
Key Features
| Feature | Design Value |
|---|---|
| AEC-Q101 qualified (H-grade option) | Validated for automotive powertrain and chassis applications per stress test requirements including HTOL, TCT, and ESD. |
| 400 W surge rating (10/1000 μs) | Withstands ISO 7637-2 Pulse 5a (load dump) up to 137 V clamping, protecting CAN/LIN transceivers and microcontrollers. |
| Low clamping ratio (VC/VBR ≈ 1.37) | Minimizes overvoltage overshoot during fast transients, reducing risk of gate oxide damage in MOSFET drivers and logic ICs. |
| RoHS & halogen-free (IEC 61249-2-21) | Complies with automotive ELV directive and IPC-J-STD-709 material restrictions for end-of-life recycling and safety. |
| Junction temperature range: –55 to +175 °C | Supports deployment in under-hood ECUs, battery management systems, and industrial motor controllers without derating. |
Applications
| Automotive Power Rail Protection | Industrial PLC Digital I/O Protection |
|---|---|
Use Scenario: Suppressing load-dump transients (ISO 7637-2 Pulse 5a) on 24 V battery-fed ECUs in commercial vehicles. IC Role / Device Role / Timing Role: Bidirectional TVS clamps both polarities of surge events to protect downstream DC-DC converters and MCU power inputs. Use Value: Limits peak voltage to 137 V during 2.9 A surge, preventing latch-up or permanent damage in 3.3 V/5 V logic supplies. |
Use Scenario: Guarding 24 V digital input channels in programmable logic controllers against inductive kickback from solenoid valves. IC Role / Device Role / Timing Role: Fast-response TVS diverts >90% of 400 W surge energy away from optocoupler input stages and signal conditioning circuits. Use Value: Enables reliable operation with <1 μA leakage at 85.5 V, avoiding false triggering in high-impedance sensing paths. |
| LED Driver Overvoltage Clamp | ESD-Protected Communication Interface |
Use Scenario: Protecting constant-current LED driver ICs in streetlight systems from lightning-induced surges on AC/DC front-end rails. IC Role / Device Role / Timing Role: Standoff-rated TVS absorbs repetitive 10/1000 μs transients without degradation, maintaining long-term reliability. Use Value: 175 °C max junction temperature allows direct mounting on metal-core PCBs near high-power LED arrays. |
Use Scenario: Adding secondary-level surge immunity to RS-485 transceivers in factory automation networks exposed to EFT bursts. IC Role / Device Role / Timing Role: Low-capacitance (typ. <100 pF at 0 V) TVS minimizes signal distortion on differential bus lines up to 10 Mbps. Use Value: Clamps ESD events (IEC 61000-4-2 ±8 kV contact) within nanoseconds, preserving data integrity without adding termination mismatch. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transient voltage suppression applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMBJ85CA (Bourns) | Same DO-214AA (SMB) package; 85 V VWM, 137 V VC @ 2.9 A, but rated for 600 W PPK and higher IPP (3.2 A). | Higher surge margin suits infrequent high-energy events (e.g., utility grid coupling); SMB footprint requires PCB redesign. | Select when board space permits SMB package and system-level testing demands >400 W headroom. |
| P6KE85CA (Littelfuse) | DO-15 package; identical VWM/VC specs but lower thermal performance (RθJA = 125 °C/W) and no AEC-Q101 option. | Limited to non-automotive industrial use due to absence of automotive qualification and reduced thermal robustness. | Choose for cost-sensitive consumer or white-goods applications where AEC-Q101 and high-temp operation are not required. |
Compared with SMBJ85CA and P6KE85CA, the BZW04-85B offers AEC-Q101 qualification and superior thermal resistance (RθJA = 100 °C/W) in the legacy DO-41 form factor - making it optimal for retrofitting existing automotive harnesses and space-constrained industrial designs requiring proven reliability.
Availability
BZW04-85B is available at Aetrix Electronics and suitable for automotive ECU protection, industrial PLC I/O hardening, and LED driver overvoltage clamping requiring stable component supply across extended production lifecycles.
Supply support for BZW04-85B 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 analog and discrete semiconductor manufacturer headquartered in Hsinchu, Taiwan, specializing in high-reliability protection devices and power management components.
The BZW04 series was engineered specifically for automotive-grade transient suppression, emphasizing AEC-Q101 compliance, wide temperature operation, and repeatable clamping performance in harsh environments - targeting engine control, body electronics, and ADAS subsystems.
FAQ
What is the polarity configuration of BZW04-85B?
The BZW04-85B is a bidirectional TVS diode, meaning it provides symmetrical clamping for both positive and negative transients without polarity sensitivity. Unlike unidirectional variants (e.g., BZW04-85), it has no cathode band marking and can be mounted in either orientation on the PCB - simplifying layout and eliminating assembly errors.
Is BZW04-85B AEC-Q101 qualified?
The base BZW04-85B part is not AEC-Q101 qualified; however, the variant BZW04-85BH (with "H" suffix) is fully AEC-Q101 qualified per Rev. J2104 documentation. Engineers specifying automotive applications must select BZW04-85BH to meet qualification requirements for powertrain and chassis systems.
What is the maximum clamping voltage of BZW04-85B at its rated surge current?
The BZW04-85B exhibits a maximum clamping voltage (VC) of 137 V when subjected to its rated peak impulse current (IPP) of 2.9 A under the standard 10/1000 μs waveform. This value is guaranteed across the full operating temperature range and forms the basis for protected circuit voltage margining.
How does BZW04-85B compare to unidirectional TVS diodes in circuit protection?
Unlike unidirectional TVS diodes such as BZW04-85, the BZW04-85B provides equal clamping performance for both polarities - essential for AC-coupled lines, floating grounds, or systems where transient polarity cannot be predicted. Its bidirectional architecture eliminates the need for dual-diode configurations or polarity-aware routing.
What packaging options are available for BZW04-85B?
BZW04-85B is supplied in DO-204AL (DO-41) package with two standard packing formats: 5,000 units per tape-and-reel (standard code) and 3,000 units per ammo box (suffix A0G). Both options feature pure tin-plated leads compliant with J-STD-002 solderability standards and RoHS/halogen-free construction.
BZW04-85B 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):
- 85.5V
- Voltage - Breakdown (Min):
- 95V
- Voltage - Clamping (Max) @ Ipp:
- 137V
- Current - Peak Pulse (10/1000µs):
- 2.9A
- 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)
BZW04-85B FAQ
1.How can I place an order for BZW04-85B through Aetrix?
Please submit a Request for Quotation (RFQ) for BZW04-85B 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 BZW04-85B reliable?
The price and inventory of BZW04-85B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZW04-85B is usually 5 days.
3.What payment methods are accepted for BZW04-85B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZW04-85B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZW04-85B?
BZW04-85B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZW04-85B 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 BZW04-85B?
For technical support, including BZW04-85B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZW04-85B requirements.
6.How does Aetrix verify that BZW04-85B is sourced from the original manufacturer or authorized distributors?
All BZW04-85B 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 BZW04-85B meets industry standards.
7.What is the process for return or replacement of BZW04-85B?
All BZW04-85B units undergo pre-shipment inspection (PSI). If there is an issue with BZW04-85B, 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 BZW04-85B part is unused and in its original packaging.
Return procedure for BZW04-85B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZW04-85B Tags
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