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onsemi BZX85C4V3
- Part No.:
- BZX85C4V3
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
BZX85C4V3.pdf
- Description:
- DIODE ZENER 4.3V 1W DO41
- Quantity:
- Payment:
- Shipping:
Inventory:4,794
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Product details
Overview
BZX85C4V3 from onsemi is a 4.3 V, ±5% tolerance, 1.0 W axial-leaded Zener diode in DO-41 glass package, designed for voltage regulation and reference applications in power supply feedback loops, overvoltage protection circuits, and precision biasing networks where stable reverse breakdown is required.
For engineers reviewing the BZX85C4V3 datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance (±5%), zener impedance (50 Ω @ 5 mA), leakage current (3 μA max @ 1 V), thermal derating (6.67 mW/°C above 50°C), and DO-41 mechanical compatibility with through-hole PCB assembly.
Technical Context
The BZX85C4V3 operates as a silicon planar Zener diode with controlled avalanche and Zener breakdown mechanisms optimized for stable 4.3 V regulation at test current IZ = 5 mA. Its junction temperature range spans −65°C to +200°C, supporting industrial and automotive under-hood environments.
It exhibits a forward voltage ≤1.2 V at 200 mA and a maximum zener impedance of 50 Ω at 5 mA, with knee impedance ZZK = 500 Ω at IZK = 1 mA - indicating sharp turn-on behavior suitable for low-current reference use.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 4.0 V min / 4.6 V max at IZ = 5 mA - defines regulated output range for feedback or clamp circuits |
| Tolerance | ±5% - ensures predictable voltage setpoint without post-calibration in cost-sensitive designs |
| Power Dissipation | 1.0 W @ TA = 25°C - supports continuous regulation in compact linear supplies without forced cooling |
| Zener Impedance | 50 Ω @ IZ = 5 mA - limits output voltage variation under load changes in reference paths |
| Leakage Current | 3 μA max @ VR = 1 V - minimizes standby power loss in battery-backed or low-power sensing nodes |
| Package | DO-41 glass case - provides hermetic sealing, high reliability, and JEDEC-standard lead spacing (25.4 mm min) |
Pinout & Package
DO-41 glass axial package with cathode indicated by color band; two-terminal device with no internal connections beyond anode and cathode leads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference ground node | Connected to circuit ground or lower-potential rail when used in shunt regulation |
| Cathode | Zener breakdown terminal / regulated output node | Connected to input voltage source and load; maintains ~4.3 V relative to anode during reverse bias |
Key Features
| Feature | Design Value |
|---|---|
| Stable 4.3 V regulation | Guaranteed 4.0–4.6 V range at 5 mA enables repeatable threshold setting in analog comparators and error amplifiers |
| Low zener impedance | 50 Ω typical improves line/load regulation in feedback networks without external compensation |
| High junction temperature rating | −65°C to +200°C operation supports deployment in engine control units and industrial motor drives |
| Hermetic glass encapsulation | DO-41 glass body resists moisture ingress and long-term parameter drift in humid environments |
Applications
| Power Supply Feedback | Overvoltage Clamp |
|---|---|
Use Scenario: Regulating output voltage in isolated flyback or buck-derived DC-DC converters using optocoupler-coupled feedback. IC Role / Device Role / Timing Role: Shunt voltage reference providing precise 4.3 V threshold to TL431 or optocoupler LED drive circuit. Use Value: Enables ±1% output accuracy without trimming resistors; DO-41 footprint simplifies layout in space-constrained secondary-side PCBs. |
Use Scenario: Protecting microcontroller I/O pins or ADC inputs from transient overvoltage events exceeding 5 V. IC Role / Device Role / Timing Role: Passive clamping element diverting excess current to ground when input exceeds 4.6 V. Use Value: Limits peak voltage to safe levels with <3 μA leakage at 1 V, preserving signal integrity in sensor interface circuits. |
| Precision Biasing | Reference Voltage Source |
Use Scenario: Generating stable bias points for op-amp input stages or transistor amplifier quiescent points. IC Role / Device Role / Timing Role: Low-drift DC reference node establishing fixed potential for analog front-end conditioning. Use Value: Delivers <50 Ω dynamic impedance to maintain bias stability across temperature and supply variations. |
Use Scenario: Providing known reference voltage to ADCs, DACs, or comparator hysteresis networks. IC Role / Device Role / Timing Role: Primary voltage reference with minimal self-heating effect due to 1.0 W dissipation limit. Use Value: Supports 12-bit resolution systems where reference deviation must stay within ±2 LSB over operating temperature. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4733A | Same 5.1 V nominal rating but different family; 1.0 W, ±5%, DO-41, ZZ = 17 Ω @ 49 mA | Higher test current shifts knee behavior - less suitable for low-current references | Prefer BZX85C4V3 where 4.3 V exact regulation and low-IZ operation are required |
| MMBZ5225B | SMD SOT-23 package, 3.0 V, 0.25 W, ±5%, ZZ = 130 Ω @ 20 mA | Surface-mount only; lower power and higher impedance limit use in high-accuracy shunt regulators | Select BZX85C4V3 for through-hole reliability, higher power handling, and tighter low-current regulation |
Compared with 1N4733A and MMBZ5225B, the BZX85C4V3 offers optimal balance of 4.3 V precision, 1.0 W capability, and DO-41 mechanical robustness for industrial power management - making it preferred for legacy-compatible designs requiring proven thermal performance and axial lead mounting.
Availability
BZX85C4V3 is available at Aetrix Electronics and suitable for power supply feedback, overvoltage protection, and precision biasing applications requiring stable component supply across extended production lifecycles.
Supply support for BZX85C4V3 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
onsemi (formerly ON Semiconductor) is a global semiconductor supplier focused on energy-efficient electronics, delivering silicon solutions for automotive, industrial, cloud, and IoT applications.
The BZX85C4V3 belongs to the BZX85C series of general-purpose Zener diodes engineered for reliable voltage regulation in cost-sensitive, high-volume power management systems.
FAQ
What is the nominal zener voltage of the BZX85C4V3?
The BZX85C4V3 has a nominal zener voltage of 4.3 V, with a guaranteed range of 4.0 V to 4.6 V at test current IZ = 5 mA and ambient temperature TA = 25°C. This value is defined per the onsemi datasheet Rev. 2 (October 2017) and reflects the device's primary function as a precision shunt regulator. The BZX85C4V3 achieves this specification using planar silicon Zener technology with tight process control.
What package type does the BZX85C4V3 use?
The BZX85C4V3 uses the DO-41 axial-leaded glass package, compliant with JEDEC DO-204AL standards. Its dimensions include 25.4 mm minimum lead spacing, 2.03–2.72 mm body diameter, and hermetically sealed glass construction. This package ensures long-term stability and moisture resistance - critical for the BZX85C4V3's use in industrial and automotive environments where reliability is paramount.
What is the maximum power dissipation rating for the BZX85C4V3?
The BZX85C4V3 has a maximum power dissipation of 1.0 W at ambient temperature TA = 25°C. Above 50°C, it must be derated at 6.67 mW/°C. This rating directly governs how much continuous current the BZX85C4V3 can safely sink while maintaining regulation - for example, at 4.3 V, it supports up to ~233 mA before reaching thermal limits. Derating ensures sustained performance in enclosed or high-temperature enclosures.
How does the BZX85C4V3 compare to the BZX85C3V3 in terms of zener voltage and impedance?
The BZX85C4V3 specifies a zener voltage range of 4.0–4.6 V at 5 mA, whereas the BZX85C3V3 is rated 3.1–3.5 V. Their zener impedances differ significantly: BZX85C4V3 has ZZ = 50 Ω, while BZX85C3V3 is 80 Ω. This means the BZX85C4V3 offers tighter regulation and lower output impedance - making it more suitable for applications demanding higher accuracy and better load regulation than those served by the BZX85C3V3.
Is the BZX85C4V3 suitable for low-current reference applications?
Yes - the BZX85C4V3 is validated for low-current operation down to IZK = 1 mA, where its knee impedance ZZK is specified at 500 Ω. With only 3 μA leakage at 1 V reverse bias, it introduces negligible error in battery-powered or ultra-low-power circuits. Its stable 4.3 V regulation at minimal current makes the BZX85C4V3 well-suited for sensor biasing, microcontroller reset thresholds, and portable equipment voltage references.
BZX85C4V3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Bulk
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 4.3 V
- Tolerance:
- ±7%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 13 Ohms
- Current - Reverse Leakage @ Vr:
- 3 µA @ 1 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.2 V @ 200 mA
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-41
BZX85C4V3 FAQ
1.How can I place an order for BZX85C4V3 through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX85C4V3 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 BZX85C4V3 reliable?
The price and inventory of BZX85C4V3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX85C4V3 is usually 5 days.
3.What payment methods are accepted for BZX85C4V3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX85C4V3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX85C4V3?
BZX85C4V3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX85C4V3 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 BZX85C4V3?
For technical support, including BZX85C4V3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX85C4V3 requirements.
6.How does Aetrix verify that BZX85C4V3 is sourced from the original manufacturer or authorized distributors?
All BZX85C4V3 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 BZX85C4V3 meets industry standards.
7.What is the process for return or replacement of BZX85C4V3?
All BZX85C4V3 units undergo pre-shipment inspection (PSI). If there is an issue with BZX85C4V3, 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 BZX85C4V3 part is unused and in its original packaging.
Return procedure for BZX85C4V3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX85C4V3 Tags
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BZT52C5V6T-7
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MMSZ5231B-7-F
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BZX84C3V3LT1G
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MMSZ4682T1G
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BZT52C15S-7-F
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MM5Z5V1ST1G
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