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onsemi BZX55C51_T50R
- Part No.:
- BZX55C51_T50R
- Manufacturer:
- onsemi
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
BZX55C51_T50R.pdf
- Description:
- DIODE ZENER 51V 500MW DO35
- Quantity:
- Payment:
- Shipping:
Inventory:7,538
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Product details
Overview
BZX55C51_T50R from Fairchild Semiconductor is a 51 V ±5% tolerance 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 reverse leakage at 38 V, used for precision voltage regulation and overvoltage protection in low-power analog circuits.
For engineers reviewing the BZX55C51_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage accuracy, thermal derating behavior, cathode-band polarity marking, and DO-35 mechanical compatibility in space-constrained PCB layouts.
Technical Context
This device operates as a two-terminal voltage reference, maintaining stable 51 V regulation across its specified reverse-bias current range (2.5 mA to 38 mA). Its 125 Ω dynamic impedance ensures predictable voltage deviation under load variation, while the -65°C to +200°C operating temperature range supports industrial and automotive ambient conditions.
The DO-35 glass package features axial leads with cathode band marking, requiring manual orientation during placement. Power dissipation is thermally limited by lead length (3/8″) and ambient temperature, with linear derating of 4.0 mW/°C above 75°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 48 V min / 54 V max at 2.5 mA - defines regulation window for feedback or clamp circuits |
| Dynamic Impedance (ZZ) | 125 Ω at IZ = 2.5 mA - determines output voltage shift per mA of load current change |
| Reverse Leakage (IR) | 0.1 μA max at VR = 38 V - ensures minimal quiescent current in high-impedance bias networks |
| Power Dissipation (PD) | 500 mW at TL ≤ 75°C - sets maximum continuous power before thermal shutdown risk |
| Tolerance | ±5% - enables use in applications requiring moderate voltage accuracy without trimming |
| Operating Temp Range | -65°C to +200°C - supports deployment in extended-temperature industrial environments |
Pinout & Package
DO-35 glass axial-leaded package with cathode indicated by a color band on one end; no active pin numbering-cathode and anode are unidirectional terminals defined by band position.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (banded end) | Reverse-bias voltage reference terminal | Connected to regulated node; must be at higher potential than anode during operation |
| Anode (unbanded end) | Reference return path | Typically tied to ground or lower-voltage rail to complete zener conduction path |
Key Features
| Feature | Design Value |
|---|---|
| Stable 51 V reference | Guaranteed 48–54 V range at 2.5 mA enables repeatable threshold setting in comparator inputs |
| Low leakage current | ≤0.1 μA at 38 V minimizes error in high-resistance voltage divider networks |
| Thermal stability | Rated for -65°C to +200°C operation, supporting reliability in under-hood or industrial enclosures |
| Standard DO-35 footprint | Enables drop-in replacement in legacy designs using axial-leaded zeners without layout revision |
Applications
| Power Supply Voltage Clamp | Overvoltage Protection Circuit |
|---|---|
Use Scenario: Clamping transient spikes on 48 V DC bus lines in telecom power modules. IC Role / Device Role / Timing Role: Zener diode acting as shunt regulator to divert excess current when voltage exceeds 51 V. Use Value: Prevents downstream IC damage by limiting peak bus voltage to 54 V with 125 Ω impedance limiting clamp current rise rate. | Use Scenario: Protecting microcontroller ADC input against ESD-induced overvoltage in sensor interface boards. IC Role / Device Role / Timing Role: Passive voltage clamp placed between signal line and ground. Use Value: 0.1 μA leakage avoids loading 10 MΩ input impedance, while 51 V breakdown triggers clamping before ADC damage threshold. |
| Reference Voltage Source | Feedback Network in Linear Regulator |
Use Scenario: Providing stable 51 V reference for op-amp-based precision current source calibration. IC Role / Device Role / Timing Role: Two-terminal voltage reference establishing fixed bias point. Use Value: ±5% tolerance and 125 Ω ZZ allow predictable offset compensation without trimming resistors. | Use Scenario: Setting output voltage in discrete 51 V linear regulator using pass transistor and feedback divider. IC Role / Device Role / Timing Role: Zener element in feedback loop defining regulated output level. Use Value: DO-35 package allows direct soldering into through-hole regulator PCBs with proven thermal performance at 500 mW. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5257B | Same 51 V nominal rating, ±5% tolerance, but 150 Ω ZZ and 100 mW lower PD (400 mW) | Lower power handling limits use in sustained clamp scenarios above 20 mA | Select when board space permits smaller DO-35 variant and thermal load is <400 mW |
| MMSZ5257B | SOD-123 surface-mount package, identical 51 V/±5%/125 Ω specs, but 500 mW derated to 350 mW at TA = 25°C | Requires rework for SMT assembly; unsuitable for through-hole legacy repairs | Choose for new SMT designs needing same electrical performance in compact footprint |
Compared with BZX55C51_T50R, 1N5257B offers identical voltage rating but reduced power margin, while MMSZ5257B matches electrical specs in SMT form-neither is pin-compatible due to differing packages, making BZX55C51_T50R the only DO-35 axial option for through-hole replacement.
Availability
BZX55C51_T50R is available at Aetrix Electronics and suitable for power supply voltage clamp, overvoltage protection circuit, and reference voltage source applications requiring stable component supply and long-term obsolescence management.
Supply support for BZX55C51_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
Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete components before its acquisition by ON Semiconductor in 2016.
The BZX55 series was designed as a general-purpose, cost-effective Zener diode family for voltage regulation and protection in industrial, telecom, and consumer electronics.
FAQ
What is the exact zener voltage range for BZX55C51_T50R at 2.5 mA test current?
The BZX55C51_T50R has a guaranteed zener voltage range of 48 V minimum to 54 V maximum when measured at 2.5 mA reverse current and 25°C ambient temperature. This ±5% tolerance reflects the C-suffix grade per the Fairchild BZX55C2V4–BZX55C56 datasheet Rev. D1, and applies directly to the BZX55C51_T50R variant.
Does BZX55C51_T50R have a specified forward voltage?
Yes, the BZX55C51_T50R specifies a maximum forward voltage (VF) of 1.3 V at 100 mA forward current, consistent with standard silicon PN junction diode behavior. This parameter is relevant when the device is inadvertently forward-biased or used in dual-role protection circuits.
What is the maximum reverse leakage current for BZX55C51_T50R, and at what voltage is it tested?
The BZX55C51_T50R exhibits a maximum reverse leakage current (IR) of 0.1 μA when tested at 38 V reverse voltage and 25°C. This value is confirmed in the "Electrical Characteristics" table of the Fairchild datasheet and defines the diode's off-state current in high-impedance clamp or reference applications.
Can BZX55C51_T50R be used in automotive under-hood applications?
Yes, BZX55C51_T50R supports automotive under-hood use due to its -65°C to +200°C operating and storage temperature range, verified in the Absolute Maximum Ratings table. However, system-level qualification (e.g., AEC-Q200) is not claimed in the Fairchild datasheet, so design-in requires independent thermal and reliability validation.
What does the "T50R" suffix indicate in BZX55C51_T50R?
The "T50R" suffix in BZX55C51_T50R denotes a tape-and-reel packaging format (T50) with 5000 units per reel (R), per Fairchild's standard ordering nomenclature. It does not affect electrical or thermal specifications-the device remains electrically identical to bulk or ammo-pack versions of BZX55C51.
BZX55C51_T50R Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Tape & Reel (TR)
- 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_T50R FAQ
1.How can I place an order for BZX55C51_T50R through Aetrix?
Please submit a Request for Quotation (RFQ) for BZX55C51_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 BZX55C51_T50R reliable?
The price and inventory of BZX55C51_T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BZX55C51_T50R is usually 5 days.
3.What payment methods are accepted for BZX55C51_T50R?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BZX55C51_T50R transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BZX55C51_T50R?
BZX55C51_T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BZX55C51_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 BZX55C51_T50R?
For technical support, including BZX55C51_T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BZX55C51_T50R requirements.
6.How does Aetrix verify that BZX55C51_T50R is sourced from the original manufacturer or authorized distributors?
All BZX55C51_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 BZX55C51_T50R meets industry standards.
7.What is the process for return or replacement of BZX55C51_T50R?
All BZX55C51_T50R units undergo pre-shipment inspection (PSI). If there is an issue with BZX55C51_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 BZX55C51_T50R part is unused and in its original packaging.
Return procedure for BZX55C51_T50R:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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