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Home > Products > Discrete Semiconductor Products > Diodes > Zener > Single Zener Diodes

onsemi 1N5251B_T50R

Name: 1N5251B_T50R
Brand: onsemi
SKU: 1N5251B_T50R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 1N5251B_T50R

Manufacturer:: onsemi

Category:: Single Zener Diodes

Package:: DO-204AH, DO-35, Axial

Datasheet:: 1N5251B_T50R.pdf

Description:: DIODE ZENER 22V 500MW DO35

Quantity:: RFQ Add To RFQ list

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Inventory:8,032

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Product details

Overview

1N5251B_T50R from ON Semiconductor is a 22 V ±5% tolerance, 500 mW glass-encapsulated Zener diode in DO-35 package, designed for precision voltage regulation and reference applications in low-power analog circuits, power supply feedback loops, and overvoltage protection. It delivers 22 V nominal Zener voltage at 19 mA test current, with 29 Ω dynamic impedance and 0.25 μA reverse leakage at 17 V.

For engineers reviewing the 1N5251B_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include Zener voltage accuracy (±5%), thermal coefficient (+0.087 %/°C), junction temperature range (–65 °C to +200 °C), and DO-35 mechanical compatibility with through-hole PCB layouts.

Technical Context

This device operates as a two-terminal silicon Zener diode optimized for stable voltage clamping and reference generation in DC bias networks. Its 22 V breakdown voltage is specified at I_Z = 19 mA with tight 5% tolerance and low dynamic impedance (29 Ω), enabling accurate regulation under moderate load variations.

The DO-35 hermetically sealed glass package ensures long-term stability and low leakage (≤0.25 μA at 17 V), while the –65 °C to +200 °C operating junction temperature range supports industrial and automotive under-hood environments where thermal robustness is critical.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	22 V nominal at I_Z = 19 mA - defines precise clamping threshold for voltage reference and regulation
Tolerance	±5% - ensures predictable voltage accuracy across production lots without trimming
Power Dissipation (P_D)	500 mW at T_A = 25 °C - sets maximum continuous DC power handling in standard ambient
Dynamic Impedance (Z_Z)	29 Ω at I_Z = 19 mA - determines regulation stiffness and output voltage variation under load changes
Reverse Leakage (I_R)	≤0.25 μA at V_R = 17 V - guarantees minimal quiescent current in standby or high-impedance bias networks
Temperature Coefficient	+0.087 %/°C - quantifies voltage drift per degree Celsius, critical for temperature-stable references
Package	DO-35 glass - provides hermetic sealing, lead-free compatible termination, and JEDEC-standard through-hole mounting

Pinout & Package

DO-35 glass axial-leaded package with cathode indicated by color band. Two-terminal device: anode and cathode are non-polarized in function but polarity-sensitive in circuit connection.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward conduction terminal / Zener cathode reference ground	Connected to lower potential node; forms reference return path in shunt regulator topologies
Cathode	Zener breakdown terminal / voltage clamp input	Connected to higher potential node; clamps voltage to 22 V when reverse-biased above breakdown

Key Features

Feature	Design Value
Precision Zener voltage	22 V ±5% at 19 mA - enables direct replacement of legacy 22 V references without recalibration
Low dynamic impedance	29 Ω - minimizes output voltage deviation during transient load steps in feedback networks
Hermetic glass encapsulation	DO-35 package - ensures moisture resistance and long-term parameter stability in humid environments
Wide operating temperature	–65 °C to +200 °C junction range - supports deployment in extended-temperature industrial and automotive applications
Controlled thermal coefficient	+0.087 %/°C - allows predictable voltage drift compensation in temperature-critical analog designs

Applications

Power Supply Feedback Reference	Overvoltage Clamp Protection
Use Scenario: Used in the error amplifier feedback network of isolated DC-DC converters to set regulated output voltage. IC Role / Device Role / Timing Role: Zener diode serves as precision voltage reference for optocoupler-based feedback loop. Use Value: 22 V nominal breakdown with ±5% tolerance ensures output voltage accuracy within ±1% over line/load conditions.	Use Scenario: Placed across sensitive IC inputs to limit transient overvoltage events from ESD or inductive switching. IC Role / Device Role / Timing Role: Shunt clamping element that conducts above 22 V to divert surge current away from downstream logic. Use Value: 500 mW power rating and 29 Ω Z_Z enable reliable clamping of 100 ns–1 μs transients up to 1 A peak.
Low-Power Analog Biasing	Current Source Reference
Use Scenario: Provides stable bias voltage for op-amp input stages or sensor excitation circuits in battery-powered instrumentation. IC Role / Device Role / Timing Role: Passive voltage reference establishing fixed DC offset in signal conditioning paths. Use Value: ≤0.25 μA leakage at 17 V preserves microamp-level standby current budgets in always-on sensors.	Use Scenario: Configured with series resistor to generate constant current for LED drivers or precision current mirrors. IC Role / Device Role / Timing Role: Stable voltage source defining current magnitude via Ohm's Law (I = V_Z/R). Use Value: +0.087 %/°C TC enables <±2% current drift over –40 °C to +85 °C ambient without active compensation.

Power Supply Feedback Reference

Overvoltage Clamp Protection

Use Scenario: Used in the error amplifier feedback network of isolated DC-DC converters to set regulated output voltage.

IC Role / Device Role / Timing Role: Zener diode serves as precision voltage reference for optocoupler-based feedback loop.

Use Value: 22 V nominal breakdown with ±5% tolerance ensures output voltage accuracy within ±1% over line/load conditions.

Use Scenario: Placed across sensitive IC inputs to limit transient overvoltage events from ESD or inductive switching.

IC Role / Device Role / Timing Role: Shunt clamping element that conducts above 22 V to divert surge current away from downstream logic.

Use Value: 500 mW power rating and 29 Ω Z_Z enable reliable clamping of 100 ns–1 μs transients up to 1 A peak.

Low-Power Analog Biasing

Current Source Reference

Use Scenario: Provides stable bias voltage for op-amp input stages or sensor excitation circuits in battery-powered instrumentation.

IC Role / Device Role / Timing Role: Passive voltage reference establishing fixed DC offset in signal conditioning paths.

Use Value: ≤0.25 μA leakage at 17 V preserves microamp-level standby current budgets in always-on sensors.

Use Scenario: Configured with series resistor to generate constant current for LED drivers or precision current mirrors.

IC Role / Device Role / Timing Role: Stable voltage source defining current magnitude via Ohm's Law (I = V_Z/R).

Use Value: +0.087 %/°C TC enables <±2% current drift over –40 °C to +85 °C ambient without active compensation.

Equivalent & Alternatives

The following parts are listed as comparable options for similar Zener diode voltage reference applications.

Alternative Part	Technical Difference	Application Difference	Selection Advice
1N4742A	12 V Zener voltage, 1 W power rating, DO-41 package	Higher power handling but lower voltage; unsuitable for 22 V reference needs	Select only if system requires 12 V clamping and higher thermal margin
BZX55C22	22 V Zener, ±5% tolerance, 500 mW, DO-35, but 30 Ω Z_Z and +0.08 %/°C TC	Nearly identical electrical specs; minor TC and Z_Z variance within design margin	Valid alternative where BZX55C22 sourcing is preferred; no layout change required

Compared with 1N5251B_T50R, the 1N4742A offers higher power but mismatched voltage, making it unsuitable as a drop-in replacement; the BZX55C22 matches voltage, tolerance, and package while differing slightly in TC (+0.08 %/°C vs. +0.087 %/°C) and Z_Z (30 Ω vs. 29 Ω), supporting functional interchangeability in most 22 V reference designs.

Availability

1N5251B_T50R is available at Aetrix Electronics and suitable for power supply feedback reference, overvoltage clamp protection, and low-power analog biasing requiring stable component supply and consistent DO-35 form factor.

Supply support for 1N5251B_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

ON Semiconductor is a global semiconductor manufacturer specializing in energy-efficient power management, analog, sensing, and connectivity solutions for automotive, industrial, cloud, and consumer markets.

The 1N52xxB series belongs to ON Semiconductor's legacy Zener diode product line, engineered for high-reliability voltage reference and regulation in cost-sensitive, space-constrained through-hole applications.

FAQ

What is the nominal Zener voltage of the 1N5251B_T50R?

The 1N5251B_T50R has a nominal Zener voltage of 22 V, specified at a test current of 19 mA, with a guaranteed tolerance of ±5%. This value is measured under thermal equilibrium conditions at lead temperature of 30°C ±1°C, ensuring repeatable performance in production calibration and circuit design.

What package type does the 1N5251B_T50R use?

The 1N5251B_T50R uses the DO-35 glass axial-leaded package, compliant with JEDEC DO-204AH standards. It features hermetic glass sealing, a cathode identification band, and mechanical dimensions optimized for manual and automated through-hole assembly.

What is the maximum power dissipation rating for the 1N5251B_T50R?

The 1N5251B_T50R has a maximum power dissipation of 500 mW at ambient temperature of 25°C. Power derating is 4.0 mW/°C above 50°C, meaning usable power drops linearly to zero at approximately 175°C ambient - a key constraint for thermal design in enclosed enclosures.

Does the 1N5251B_T50R have a specified temperature coefficient?

Yes, the 1N5251B_T50R has a positive temperature coefficient of +0.087 %/°C, indicating its Zener voltage increases by 0.087% per degree Celsius rise in junction temperature. This value is critical for predicting voltage drift in temperature-varying applications such as automotive engine control units.

What is the reverse leakage current specification for the 1N5251B_T50R?

The 1N5251B_T50R specifies a maximum reverse leakage current of 0.25 μA at a reverse voltage of 17 V and ambient temperature of 25°C. This ultra-low leakage supports high-impedance bias networks and battery-operated systems where standby current must remain below 1 μA.

1N5251B_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):: 22 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 29 Ohms

Current - Reverse Leakage @ Vr:: 100 nA @ 17 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-35

1N5251B_T50R FAQ

1.How can I place an order for 1N5251B_T50R through Aetrix?

Please submit a Request for Quotation (RFQ) for 1N5251B_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 1N5251B_T50R reliable?

The price and inventory of 1N5251B_T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5251B_T50R is usually 5 days.

3.What payment methods are accepted for 1N5251B_T50R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5251B_T50R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 1N5251B_T50R?

1N5251B_T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1N5251B_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 1N5251B_T50R?

For technical support, including 1N5251B_T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5251B_T50R requirements.

6.How does Aetrix verify that 1N5251B_T50R is sourced from the original manufacturer or authorized distributors?

All 1N5251B_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 1N5251B_T50R meets industry standards.

7.What is the process for return or replacement of 1N5251B_T50R?

All 1N5251B_T50R units undergo pre-shipment inspection (PSI). If there is an issue with 1N5251B_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 1N5251B_T50R part is unused and in its original packaging.

Return procedure for 1N5251B_T50R:

1.Submit a request within 90 days.

2.Obtain a Return Material Authorization (RMA) from Aetrix.

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