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

onsemi 1N5229B_T50R

Name: 1N5229B_T50R
Brand: onsemi
SKU: 1N5229B_T50R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 1N5229B_T50R

Manufacturer:: onsemi

Category:: Single Zener Diodes

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

Datasheet:: 1N5229B_T50R.pdf

Description:: DIODE ZENER 4.3V 500MW DO35

Quantity:: RFQ Add To RFQ list

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Inventory:2,232

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Product details

Overview

1N5229B_T50R from ON Semiconductor is a 4.3 V ±5% Zener diode in DO-35 glass package, rated for 500 mW power dissipation, 22 Ω dynamic impedance at 20 mA test current, and -0.055 %/°C temperature coefficient. It provides precision voltage regulation in low-power analog reference and overvoltage protection circuits.

For engineers reviewing the 1N5229B_T50R datasheet, pinout, applications, or equivalent options, this part serves as a standard 4.3 V Zener reference with verified thermal stability, DO-35 mechanical compatibility, and legacy Fairchild/ON Semiconductor cross-reference traceability.

Technical Context

The 1N5229B_T50R operates as a silicon planar Zener diode optimized for stable reverse-breakdown regulation at nominal 4.3 V. Its design targets low-current (<20 mA) reference applications where tight tolerance (±5%), predictable TC (-0.055 %/°C), and low leakage (<5 μA at 3.4 V) are required.

It features a hermetically sealed DO-35 glass package with cathode band marking, supports lead-free soldering (230 °C for 10 s), and maintains junction operation from -65 °C to +200 °C - enabling use in industrial and automotive ambient environments without derating below 50 °C.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	4.3 V nominal, min 4.085 V / max 4.515 V at I_Z = 20 mA - defines precise regulation threshold for feedback or clamp circuits
Power Dissipation (P_D)	500 mW at T_A = 25 °C - sets maximum continuous DC power handling before thermal shutdown risk
Dynamic Impedance (Z_Z)	22 Ω at I_Z = 20 mA - determines output voltage variation under load current changes
Temperature Coefficient (TC)	-0.055 %/°C - quantifies V_Z drift per degree Celsius, critical for temperature-stable references
Reverse Leakage (I_R)	5.0 μA max at V_R = 3.4 V - ensures minimal parasitic current in high-impedance bias networks
Package	DO-35 glass case - industry-standard axial leaded form factor with cathode band, compatible with manual and automated through-hole assembly

Pinout & Package

DO-35 glass package: axial-leaded, hermetically sealed, 0.533 mm diameter body, 4.56 mm length, cathode indicated by color band. Weight: 0.137 g.

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 reverse-biased regulation configuration
Cathode	Zener breakdown terminal / voltage reference output node	Delivers regulated 4.3 V relative to anode; marked by visible color band on DO-35 body

Key Features

Feature	Design Value
±5% Zener voltage tolerance	Enables accurate voltage clamping or reference generation without external trimming in cost-sensitive designs
-0.055 %/°C temperature coefficient	Minimizes V_Z drift across -65 °C to +125 °C operating range, supporting stable performance in unregulated thermal environments
22 Ω dynamic impedance at 20 mA	Ensures <110 mV output variation for ±5 mA load current shifts - suitable for precision biasing of op-amps or comparators
500 mW power rating with 4.0 mW/°C derating above 50 °C	Allows safe operation up to 175 °C ambient when derated, extending usability in enclosed or high-temperature PCB layouts

Applications

Low-Voltage Reference Source	Overvoltage Clamp Protection
Use Scenario: Providing stable 4.3 V reference for ADC voltage dividers or op-amp bias networks in battery-powered sensors. IC Role / Device Role / Timing Role: Zener diode operating in reverse breakdown to generate fixed reference potential. Use Value: Delivers ±5% initial accuracy and -0.055 %/°C TC, reducing calibration overhead in portable instrumentation.	Use Scenario: Clamping microcontroller I/O pins against ESD-induced transients exceeding 3.3 V logic rails. IC Role / Device Role / Timing Role: Shunt protection device that conducts excess energy to ground when input exceeds 4.3 V. Use Value: Limits peak voltage to 4.515 V (max V_Z) while maintaining <5 μA leakage at 3.4 V - preserving signal integrity during normal operation.
Linear Regulator Feedback	Power Supply Startup Sequencing
Use Scenario: Setting output voltage of adjustable LDOs (e.g., LM317) via resistor divider anchored to 4.3 V reference. IC Role / Device Role / Timing Role: Precision voltage reference node in feedback loop controlling pass transistor conduction. Use Value: 22 Ω Z_Z ensures <100 mV error under 4.5 mA divider current - meeting typical LDO feedback accuracy requirements.	Use Scenario: Enabling delayed enable signal generation using RC timing into a comparator with 4.3 V threshold. IC Role / Device Role / Timing Role: Stable voltage threshold element defining turn-on point for sequenced power domains. Use Value: Tight 4.085–4.515 V window and low TC ensure consistent timing across temperature, avoiding premature or late sequencing events.

Low-Voltage Reference Source

Overvoltage Clamp Protection

Use Scenario: Providing stable 4.3 V reference for ADC voltage dividers or op-amp bias networks in battery-powered sensors.

IC Role / Device Role / Timing Role: Zener diode operating in reverse breakdown to generate fixed reference potential.

Use Value: Delivers ±5% initial accuracy and -0.055 %/°C TC, reducing calibration overhead in portable instrumentation.

Use Scenario: Clamping microcontroller I/O pins against ESD-induced transients exceeding 3.3 V logic rails.

IC Role / Device Role / Timing Role: Shunt protection device that conducts excess energy to ground when input exceeds 4.3 V.

Use Value: Limits peak voltage to 4.515 V (max V_Z) while maintaining <5 μA leakage at 3.4 V - preserving signal integrity during normal operation.

Linear Regulator Feedback

Power Supply Startup Sequencing

Use Scenario: Setting output voltage of adjustable LDOs (e.g., LM317) via resistor divider anchored to 4.3 V reference.

IC Role / Device Role / Timing Role: Precision voltage reference node in feedback loop controlling pass transistor conduction.

Use Value: 22 Ω Z_Z ensures <100 mV error under 4.5 mA divider current - meeting typical LDO feedback accuracy requirements.

Use Scenario: Enabling delayed enable signal generation using RC timing into a comparator with 4.3 V threshold.

IC Role / Device Role / Timing Role: Stable voltage threshold element defining turn-on point for sequenced power domains.

Use Value: Tight 4.085–4.515 V window and low TC ensure consistent timing across temperature, avoiding premature or late sequencing events.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
1N4733A	5.1 V nominal, 5% tolerance, 17 Ω Z_Z, +0.05 %/°C TC, DO-41 package	Higher voltage, higher power (1 W), larger DO-41 footprint	Select when 5.1 V regulation or higher power margin is required; not drop-in due to package and voltage mismatch
BZX55-C4V3	4.3 V nominal, 5% tolerance, 90 Ω Z_Z, -0.06 %/°C TC, DO-35 package	Same package and voltage grade but higher impedance and tighter TC spec	Acceptable functional alternative in space-constrained DO-35 layouts where 22 Ω vs. 90 Ω Z_Z impact is acceptable

Compared with 1N5229B_T50R, 1N4733A offers higher power and voltage but requires PCB layout change; BZX55-C4V3 matches DO-35 form factor and voltage but trades lower dynamic impedance for slightly improved TC - making it viable only where impedance sensitivity is low.

Availability

1N5229B_T50R is available at Aetrix Electronics and suitable for low-power voltage reference, overvoltage protection, and linear regulator feedback applications requiring stable component supply and long-term obsolescence management.

Supply support for 1N5229B_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 supplier delivering energy-efficient power, analog, sensor, and connectivity solutions for automotive, industrial, cloud, medical, and IoT applications.

The 1N52xxB series belongs to ON Semiconductor's legacy Zener diode product line, designed specifically for general-purpose voltage regulation and reference functions in cost-sensitive, low-to-medium power analog circuits.

FAQ

What is the nominal Zener voltage of the 1N5229B_T50R?

The 1N5229B_T50R has a nominal Zener voltage of 4.3 V, with a guaranteed range of 4.085 V to 4.515 V at 20 mA test current and ±5% tolerance. This value is specified under thermal equilibrium conditions at lead temperature of 30°C ± 1°C, per ON Semiconductor's electrical characteristics table.

Is the 1N5229B_T50R RoHS compliant and lead-free solderable?

Yes, the 1N5229B_T50R is RoHS compliant and rated for lead-free soldering at 230°C for 10 seconds, as confirmed in the Absolute Maximum Ratings section of the ON Semiconductor datasheet. Its DO-35 glass package meets JEDEC DO-204AH standards and supports standard reflow and hand-soldering processes.

What is the maximum reverse leakage current for the 1N5229B_T50R?

The 1N5229B_T50R exhibits a maximum reverse leakage current of 5.0 μA at V_R = 3.4 V, as specified in the Electrical Characteristics table. This low leakage supports high-impedance bias networks and minimizes quiescent current in battery-operated systems.

Does the 1N5229B_T50R have a specified temperature coefficient?

Yes, the 1N5229B_T50R has a temperature coefficient of -0.055 %/°C, meaning its Zener voltage decreases by approximately 2.365 mV per °C rise in junction temperature. This value is measured and guaranteed across the operating range and enables predictable compensation in thermally varying environments.

Can the 1N5229B_T50R be used in place of the original Fairchild 1N5229B?

Yes, the 1N5229B_T50R is the ON Semiconductor replacement for the Fairchild 1N5229B following the Fairchild integration. The underscore in "1N5229B_T50R" reflects legacy Fairchild nomenclature; ON Semiconductor now uses hyphens (e.g., 1N5229B-T50R), but electrical, mechanical, and thermal specifications remain identical per the consolidated datasheet.

1N5229B_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):: 4.3 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 22 Ohms

Current - Reverse Leakage @ Vr:: 5 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-35

1N5229B_T50R FAQ

1.How can I place an order for 1N5229B_T50R through Aetrix?

Please submit a Request for Quotation (RFQ) for 1N5229B_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 1N5229B_T50R reliable?

The price and inventory of 1N5229B_T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5229B_T50R is usually 5 days.

3.What payment methods are accepted for 1N5229B_T50R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5229B_T50R transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 1N5229B_T50R?

1N5229B_T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1N5229B_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 1N5229B_T50R?

For technical support, including 1N5229B_T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5229B_T50R requirements.

6.How does Aetrix verify that 1N5229B_T50R is sourced from the original manufacturer or authorized distributors?

All 1N5229B_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 1N5229B_T50R meets industry standards.

7.What is the process for return or replacement of 1N5229B_T50R?

All 1N5229B_T50R units undergo pre-shipment inspection (PSI). If there is an issue with 1N5229B_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 1N5229B_T50R part is unused and in its original packaging.

Return procedure for 1N5229B_T50R:

1.Submit a request within 90 days.

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

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