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onsemi BZX85C12-T50R
- Part No.:
- BZX85C12-T50R
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AL, DO-41, Axial
- Datasheet:
-
BZX85C12-T50R.pdf
- Description:
- DIODE ZENER 12V 1W DO41
- Quantity:
- Payment:
- Shipping:
Inventory:8,846
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Product details
Overview
BZX85C12-T50R from onsemi is a 12 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 breakdown voltage and low dynamic impedance are required.
For engineers reviewing the BZX85C12-T50R datasheet, pinout, applications, or equivalent options, key selection considerations include its 12.0 V nominal Zener voltage at 5 mA test current, 20 Ω maximum Zener impedance at IZ, 0.5 μA maximum leakage at 9.1 V reverse bias, 1.0 W power dissipation at 25°C ambient, and DO-41 mechanical compatibility with standard through-hole PCB layouts.
Technical Context
The BZX85C12-T50R operates as a silicon planar Zener diode with controlled avalanche breakdown at 12 V, specified under thermal equilibrium conditions at lead temperature (TL) = 30°C ±1°C and 3/8″ lead length. Its Zener voltage tolerance is tightly controlled at ±5%, and it exhibits a typical knee current (IZK) of 0.5 mA with ZZK ≤ 350 Ω.
It supports continuous DC operation within -65°C to +200°C junction/storage temperature range and derates linearly at 6.67 mW/°C above 50°C ambient. The device is not intended for transient suppression but for stable DC voltage reference and regulation functions requiring predictable, repeatable breakdown characteristics.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 11.4 V min / 12.7 V max at IZ = 5 mA - defines usable regulation window for feedback or clamping |
| Zener Impedance (ZZ) | 20 Ω max at IZ = 5 mA - ensures minimal output voltage variation under load changes |
| Leakage Current (IR) | 0.5 μA max at VR = 9.1 V - guarantees low standby power loss in high-impedance bias networks |
| Power Dissipation (PD) | 1.0 W at TA = 25°C - sets maximum continuous DC power handling in free-air mounting |
| Package | DO-41 glass case with cathode band - enables manual or automated through-hole assembly and visual polarity identification |
| Operating Temperature | -65°C to +200°C - supports deployment in automotive engine compartments and industrial control enclosures |
Pinout & Package
DO-41 glass axial package: anode and cathode leads extend symmetrically from opposite ends of cylindrical glass body; cathode identified by single black band near one lead end.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Current entry terminal in forward bias; connected to lower-potential node in Zener mode | Must be held at least 1.2 V below cathode to avoid forward conduction; ties to ground or common return in shunt regulator |
| Cathode | Current exit terminal in forward bias; higher-potential terminal in Zener breakdown mode | Connected to regulated output or voltage reference point; marked with visible band for unambiguous orientation |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Enables direct use in cost-sensitive designs without post-production trimming or calibration |
| Low Zener impedance (20 Ω) | Maintains regulation accuracy better than ±0.1 V across 1–10 mA load current variations |
| DO-41 glass package | Provides hermetic sealing, high reliability, and compatibility with legacy through-hole reflow and wave solder processes |
| 1.0 W power rating | Supports robust operation in 5–24 V DC power rails without external heat sinking in most PCB layouts |
Applications
| Switch-Mode Power Supply Feedback | Industrial Sensor Biasing |
|---|---|
Use Scenario: Used in optocoupler-coupled feedback loop of isolated 12 V DC-DC converter to regulate output voltage. IC Role / Device Role / Timing Role: Zener reference element setting error amplifier threshold in TL431-based secondary-side regulation. Use Value: Delivers stable 12 V reference with <0.5% drift over -40°C to +85°C, enabling ±1% output regulation. |
Use Scenario: Provides precise bias voltage for bridge-type pressure sensor excitation in factory automation transmitters. IC Role / Device Role / Timing Role: Shunt voltage reference establishing constant 12 V excitation across Wheatstone bridge elements. Use Value: Maintains <10 ppm/°C effective TC via matched impedance and low leakage, minimizing zero-drift errors. |
| Overvoltage Clamp for MCU I/O | Programmable Threshold Detector |
Use Scenario: Protects 3.3 V microcontroller GPIO pins against accidental 12 V bus coupling in automotive body control modules. IC Role / Device Role / Timing Role: Bidirectional transient clamp (with series resistor) limiting pin voltage to safe levels during fault events. Use Value: Clamps at 12.7 V max while drawing <1 mA leakage at 3.3 V, preventing false triggering or latch-up. |
Use Scenario: Sets trip point for comparator monitoring battery voltage in portable medical devices. IC Role / Device Role / Timing Role: Precision reference input to LM393 comparator detecting when Li-ion pack drops below 12.0 V. Use Value: Enables 12.0 V ±0.6 V detection window with <0.1 V hysteresis margin, avoiding oscillation near threshold. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4742A | 12 V, ±5%, 1.0 W, DO-41, but ZZ = 22 Ω max at 21 mA (higher test current) | Higher test current shifts operating point; less suitable for low-current bias networks | Prefer BZX85C12-T50R when regulation must be stable at 1–5 mA; choose 1N4742A only if circuit delivers ≥20 mA Zener current |
| BZX55C12 | 12 V, ±5%, 500 mW, DO-35 glass package, ZZ = 25 Ω max at 5 mA | Lower power rating limits use in >0.5 W dissipation scenarios; smaller DO-35 footprint | Select BZX85C12-T50R for higher-power regulation; use BZX55C12 only where board space is constrained and power <0.4 W |
Compared with 1N4742A and BZX55C12, the BZX85C12-T50R offers optimal balance of 1.0 W capability, low 5 mA ZZ, and DO-41 robustness-making it preferred for industrial power supplies and sensor interfaces where thermal margin and low-current stability matter.
Availability
BZX85C12-T50R is available at Aetrix Electronics and suitable for industrial power supplies, automotive body electronics, and precision sensor signal conditioning requiring stable component supply and long-term manufacturing continuity.
Supply support for BZX85C12-T50R 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 specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.
The BZX85C12-T50R belongs to the BZX85C series of general-purpose Zener diodes engineered for reliable DC voltage regulation and reference in cost-sensitive, high-volume applications across industrial and automotive sectors.
FAQ
What is the Zener voltage tolerance for BZX85C12-T50R?
The BZX85C12-T50R has a guaranteed Zener voltage tolerance of ±5% at IZ = 5 mA, meaning its breakdown voltage falls between 11.4 V and 12.7 V under specified thermal test conditions. This tolerance is verified per JEDEC JESD22-A108 and applies across the full operating temperature range, making BZX85C12-T50R suitable for applications requiring predictable regulation without post-manufacturing calibration.
Can BZX85C12-T50R be used in surface-mount designs?
No, the BZX85C12-T50R is exclusively offered in the axial DO-41 glass package and is not compatible with surface-mount assembly processes. It requires through-hole mounting with 0.4" (10.16 mm) lead spacing. For SMT alternatives, consider the MMBZ5242B (SOT-23, 12 V) or NZ9F12V (SOD-123, 12 V), but note these differ in power rating, impedance, and thermal behavior versus the BZX85C12-T50R.
What is the maximum leakage current for BZX85C12-T50R at 9.1 V?
The BZX85C12-T50R specifies a maximum leakage current (IR) of 0.5 μA at VR = 9.1 V and TA = 25°C. This low leakage ensures minimal loading on high-impedance nodes such as op-amp inputs or comparator references, preserving accuracy in precision analog circuits where the BZX85C12-T50R serves as a stable voltage reference.
How does the power derating work for BZX85C12-T50R above 50°C?
The BZX85C12-T50R derates linearly at 6.67 mW/°C above 50°C ambient temperature. Starting from its full 1.0 W rating at 25°C, power capability reduces to approximately 0.87 W at 70°C and 0.67 W at 100°C. This derating curve is defined in the Absolute Maximum Ratings table and must be applied in thermal design to prevent junction overheating and ensure long-term reliability of the BZX85C12-T50R.
Is BZX85C12-T50R suitable for transient voltage suppression?
No, the BZX85C12-T50R is not designed or rated for transient voltage suppression (TVS). It lacks the peak pulse power rating, clamping response time, and surge current capability required for ESD or lightning-induced transients. For such applications, dedicated TVS diodes like P6KE12A or SMAJ12A should be used instead; the BZX85C12-T50R is strictly intended for steady-state DC voltage regulation and reference functions.
BZX85C12-T50R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AL, DO-41, Axial
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 12 V
- Tolerance:
- ±5%
- Power - Max:
- 1 W
- Impedance (Max) (Zzt):
- 9 Ohms
- Current - Reverse Leakage @ Vr:
- 500 nA @ 8.4 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
BZX85C12-T50R FAQ
1.How can I place an order for BZX85C12-T50R through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX85C12-T50R 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 BZX85C12-T50R reliable?
The price and inventory of BZX85C12-T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX85C12-T50R is usually 5 days.
3.What payment methods are accepted for BZX85C12-T50R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX85C12-T50R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX85C12-T50R?
BZX85C12-T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX85C12-T50R 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 BZX85C12-T50R?
For technical support, including BZX85C12-T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX85C12-T50R requirements.
6.How does Aetrix verify that BZX85C12-T50R is sourced from the original manufacturer or authorized distributors?
All BZX85C12-T50R 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 BZX85C12-T50R meets industry standards.
7.What is the process for return or replacement of BZX85C12-T50R?
All BZX85C12-T50R units undergo pre-shipment inspection (PSI). If there is an issue with BZX85C12-T50R, 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 BZX85C12-T50R part is unused and in its original packaging.
Return procedure for BZX85C12-T50R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX85C12-T50R Tags
-
MMBZ5240B-7-F
Diodes Incorporated
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BZT52C5V6T-7
Diodes Incorporated
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MMSZ5231B-7-F
Diodes Incorporated
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BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
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MMSZ4682T1G
onsemi
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BZT52C15S-7-F
Diodes Incorporated
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MM5Z5V1ST1G
onsemi
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SMAJ4744A-TP
Micro Commercial Co
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BZT52C3V6LP-7
Diodes Incorporated
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SMAZ12-13-F
Diodes Incorporated
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