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onsemi BZX55C51_T50A
- Part No.:
- BZX55C51_T50A
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
BZX55C51_T50A.pdf
- Description:
- DIODE ZENER 51V 500MW DO35
- Quantity:
- Payment:
- Shipping:
Inventory:7,711
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Product details
Overview
BZX55C51_T50A from Fairchild Semiconductor is a 51 V ±5% tolerance silicon Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C, with 125 Ω dynamic impedance at 2.5 mA test current and 0.1 μA maximum reverse leakage at 38 V. It provides precise voltage regulation in low-power reference and protection circuits.
For engineers reviewing the BZX55C51_T50A datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance, power derating behavior above 75°C, cathode identification via color band, junction temperature range (–65°C to +200°C), and compatibility with through-hole PCB assembly using 3/8″ lead length.
Technical Context
The BZX55C51_T50A operates as a two-terminal voltage reference device relying on controlled reverse-biased avalanche breakdown. Its zener voltage is specified at 2.5 mA test current, with dynamic impedance measured under identical conditions.
It exhibits 0.1 μA reverse leakage at VR = 38 V and supports forward conduction up to 1.3 V at 100 mA. Thermal performance is defined by a 4.0 mW/°C derating factor above 75°C ambient lead temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 48 V min / 54 V max at IZ = 2.5 mA - defines stable regulation window under nominal bias |
| Dynamic Impedance (ZZ) | 125 Ω max at IZ = 2.5 mA - indicates voltage stability under small-signal load variation |
| Power Dissipation (PD) | 500 mW @ TL ≤ 75°C - sets maximum continuous thermal load in standard lead-mount configuration |
| Reverse Leakage (IR) | 0.1 μA max @ VR = 38 V - ensures minimal parasitic current in standby or high-impedance sensing nodes |
| Junction Temp Range | –65°C to +200°C - enables operation in extended industrial and automotive under-hood environments |
| Forward Voltage (VF) | 1.3 V max @ IF = 100 mA - supports use as clamping diode in bidirectional transient suppression |
Pinout & Package
DO-35 glass axial package with cathode identified by a single color band. Leads are tinned copper alloy, suitable for wave or hand soldering. Package dimensions comply with JEDEC DO-35 standard (length ≈ 4.2 mm, diameter ≈ 2.0 mm).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Positive terminal in forward bias; connected to lower-potential node in zener regulation | Accepts current flow toward cathode during reverse breakdown or forward conduction |
| Cathode | Negative terminal in forward bias; connected to higher-potential node in zener regulation | Identified by color band; carries regulated output voltage when used as shunt reference |
Key Features
| Feature | Design Value |
|---|---|
| ±5% Zener voltage tolerance | Enables predictable regulation without post-production trimming in cost-sensitive designs |
| DO-35 glass encapsulation | Provides hermetic sealing and stable long-term parametric drift under thermal cycling |
| 1.3 V forward voltage limit | Allows dual-use as overvoltage clamp and low-drop rectifier in auxiliary signal paths |
| 4.0 mW/°C thermal derating | Permits accurate power budgeting in thermally constrained enclosures or high-ambient environments |
Applications
| Power Supply Reference | Overvoltage Protection |
|---|---|
Use Scenario: Low-current voltage reference in linear regulator feedback networks or analog sensor excitation circuits. IC Role / Device Role / Timing Role: Shunt voltage reference providing stable 51 V setpoint for error amplifier comparison. Use Value: Maintains ±5% output accuracy across –65°C to +125°C operating range without external calibration. | Use Scenario: Clamping transient surges on 48 V DC bus lines in industrial control modules. IC Role / Device Role / Timing Role: Bidirectional voltage limiter absorbing energy during ESD or inductive kick events. Use Value: Limits peak voltage to ≤54 V while drawing <0.1 μA leakage at normal operating voltage (38 V). |
| Signal Level Shifting | Current Source Biasing |
Use Scenario: Generating fixed offset voltages for op-amp input stages in precision instrumentation. IC Role / Device Role / Timing Role: Passive level translator establishing DC bias point between mismatched rail domains. Use Value: Delivers stable 51 V reference with 125 Ω dynamic impedance, minimizing gain error in high-Z feedback paths. | Use Scenario: Setting constant current in LED driver or photodiode transimpedance amplifier bias networks. IC Role / Device Role / Timing Role: Voltage-controlled current source element via series resistor and zener drop. Use Value: Enables 1% current accuracy with 500 mW power headroom and full-temperature-range stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5239B | Same 51 V nominal rating, ±5% tolerance, but rated for 500 mW at 25°C only; no explicit derating curve provided | Less suitable for high-temperature environments (>75°C) due to missing thermal derating specification | Select BZX55C51_T50A when operation above 75°C ambient is required |
| MMSZ5239B | SOD-123 surface-mount package; same 51 V / ±5% spec but lower 350 mW power rating | Designed for space-constrained PCB layouts; not compatible with through-hole assembly | Choose BZX55C51_T50A for legacy through-hole designs or where DO-35 mechanical robustness is preferred |
Compared with 1N5239B and MMSZ5239B, the BZX55C51_T50A offers verified thermal derating (4.0 mW/°C above 75°C) and DO-35 mechanical reliability, making it preferable for industrial power supplies and high-temperature sensor interfaces where long-term parametric stability is critical.
Availability
BZX55C51_T50A is available at Aetrix Electronics and suitable for industrial power supply references, overvoltage protection circuits, signal level shifting, and current source biasing requiring stable component supply and long-lifecycle support.
Supply support for BZX55C51_T50A 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
Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, signal conditioning, and discrete components before its acquisition by ON Semiconductor in 2016.
The BZX55 series was developed as a general-purpose, low-cost Zener diode family targeting voltage regulation and protection in consumer, industrial, and computing applications with emphasis on consistency and manufacturability.
FAQ
What is the zener voltage tolerance of BZX55C51_T50A?
The BZX55C51_T50A has a nominal zener voltage of 51 V with a guaranteed tolerance of ±5%, meaning the actual VZ falls between 48 V and 54 V when measured at 2.5 mA test current and 25°C. This tolerance is maintained across the full operating temperature range and is confirmed in the Fairchild BZX55C2V4–BZX55C56 datasheet Rev. D1.
Does BZX55C51_T50A support operation above 75°C?
Yes, BZX55C51_T50A supports operation above 75°C with defined thermal derating: power dissipation must be reduced by 4.0 mW per degree Celsius above 75°C lead temperature. Its junction temperature range extends to +200°C, enabling reliable use in high-ambient industrial environments when mounted with 3/8″ lead length.
How is the cathode identified on BZX55C51_T50A?
The cathode of BZX55C51_T50A is marked by a single color band on the DO-35 glass body. This band aligns with standard polarity marking conventions for axial-leaded Zener diodes and must be connected to the higher-potential node in shunt regulation configurations. The anode is the unmarked end.
What is the maximum reverse leakage current for BZX55C51_T50A?
The maximum reverse leakage current for BZX55C51_T50A is 0.1 μA when biased at 38 V (VR), measured at 25°C. This low leakage ensures minimal loading on high-impedance reference nodes and supports accurate voltage sensing in battery-powered or low-power systems.
Can BZX55C51_T50A be used in forward conduction mode?
Yes, BZX55C51_T50A can conduct in forward bias with a maximum forward voltage of 1.3 V at 100 mA. This capability allows dual-use as both a Zener reference and a low-drop rectifier or clamping diode in bidirectional protection circuits, provided forward current remains within safe operating limits.
BZX55C51_T50A Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Tape & Box (TB)
- Product Status:
- Obsolete
- Voltage - Zener (Nom) (Vz):
- 51 V
- Tolerance:
- ±6%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 125 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 38 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.3 V @ 100 mA
- Operating Temperature:
- -65°C ~ 200°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-35
BZX55C51_T50A FAQ
1.How can I place an order for BZX55C51_T50A through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX55C51_T50A 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 BZX55C51_T50A reliable?
The price and inventory of BZX55C51_T50A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX55C51_T50A is usually 5 days.
3.What payment methods are accepted for BZX55C51_T50A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX55C51_T50A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX55C51_T50A?
BZX55C51_T50A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX55C51_T50A 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 BZX55C51_T50A?
For technical support, including BZX55C51_T50A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX55C51_T50A requirements.
6.How does Aetrix verify that BZX55C51_T50A is sourced from the original manufacturer or authorized distributors?
All BZX55C51_T50A 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 BZX55C51_T50A meets industry standards.
7.What is the process for return or replacement of BZX55C51_T50A?
All BZX55C51_T50A units undergo pre-shipment inspection (PSI). If there is an issue with BZX55C51_T50A, 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 BZX55C51_T50A part is unused and in its original packaging.
Return procedure for BZX55C51_T50A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
BZX55C51_T50A Tags
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