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

onsemi 1N5998B_T50A

Name: 1N5998B_T50A
Brand: onsemi
SKU: 1N5998B_T50A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 1N5998B_T50A

Manufacturer:: onsemi

Category:: Single Zener Diodes

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

Datasheet:: 1N5998B_T50A.pdf

Description:: DIODE ZENER 8.2V 500MW DO35

Quantity:: RFQ Add To RFQ list

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Product details

Overview

1N5998B_T50A from Fairchild Semiconductor is a 5% tolerance, 7.79 V nominal Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C with 4.0 mW/°C derating, used for precision voltage regulation and reference in low-power analog circuits.

For engineers reviewing the 1N5998B_T50A datasheet, pinout, applications, or equivalent options, this page delivers verified Zener voltage (7.79 V min / 8.61 V max), test current (5 mA), zener impedance (7 Ω @ IZ), leakage current (0.5 mA @ 6.5 V), and thermal operating range (–65°C to +200°C) - all critical for stable biasing and voltage clamping designs.

Technical Context

This discrete Zener diode operates in reverse breakdown mode with tightly controlled V_Z tolerance (±5%) and low dynamic impedance (7 Ω at 5 mA), enabling accurate voltage reference generation in linear regulators and feedback networks. Its DO-35 glass package provides hermetic sealing and stable long-term parametric drift.

The device exhibits 0.5 mA maximum leakage current at 6.5 V (VR), supports 61 mA maximum Zener current (IZM), and maintains thermal stability across –65°C to +200°C operating and storage range - suitable for industrial and automotive under-hood applications where ambient temperature extremes occur.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	7.79 V (min) to 8.61 V (max) at 5 mA - defines precise clamping/reference threshold for analog signal conditioning.
Power Dissipation (P_D)	500 mW @ TL ≤ 75°C - sets maximum continuous power handling before thermal derating begins.
Zener Impedance (Z_Z)	7 Ω @ I_Z = 5 mA - ensures minimal output voltage variation under load changes in reference circuits.
Leakage Current (I_R)	0.5 mA @ V_R = 6.5 V - quantifies reverse-bias conduction loss below breakdown, critical for low-power standby operation.
Max Zener Current (I_ZM)	61 mA - determines absolute peak current capability before thermal runaway under worst-case V_Z and derating.
Operating Temp Range	–65°C to +200°C - enables deployment in harsh environments including engine control units and industrial sensors.
Forward Voltage (V_F)	1.2 V max @ I_F = 200 mA - specifies forward conduction drop when used as ESD clamp or polarity protection diode.

Pinout & Package

DO-35 glass axial package with cathode indicated by color band; two-terminal device requiring no orientation-specific PCB layout beyond standard axial lead spacing.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Reverse-bias reference node	Connected to lower potential side in Zener regulation; forms reference ground return path in shunt regulator topologies.
Cathode	Zener breakdown terminal	Connected to higher potential side; voltage at cathode relative to anode defines regulated output level in clamp/reference configurations.

Key Features

Feature	Design Value
±5% Zener voltage tolerance	Enables tight regulation without external trimming in cost-sensitive voltage reference designs.
7 Ω dynamic impedance at 5 mA	Minimizes output voltage deviation under varying load currents in feedback loops and sensor excitation circuits.
0.5 mA leakage at 6.5 V	Reduces quiescent power loss in battery-powered systems where standby current must remain sub-mA.
DO-35 hermetic glass package	Provides long-term parameter stability and moisture resistance for high-reliability industrial deployments.
–65°C to +200°C operating range	Supports direct mounting on heat-generating components (e.g., power MOSFET heatsinks) without derating penalties.

Applications

Low-Power Voltage Reference	Overvoltage Clamp
Use Scenario: Providing stable 7.79 V reference for ADC biasing and op-amp feedback networks in portable instrumentation. IC Role / Device Role / Timing Role: Shunt voltage reference element establishing fixed DC potential independent of supply fluctuations. Use Value: ±5% V_Z tolerance and 7 Ω impedance ensure <±10 mV output shift over 1–5 mA load range, preserving measurement accuracy.	Use Scenario: Protecting microcontroller I/O pins from transient overvoltage events exceeding 8.61 V in industrial control panels. IC Role / Device Role / Timing Role: Reverse-biased clamping diode diverting surge current away from sensitive inputs during ESD or inductive kickback. Use Value: 61 mA I_ZM rating and 1.2 V forward drop allow safe energy absorption without latch-up or permanent damage.
Linear Regulator Feedback	Temperature-Stable Bias Generator
Use Scenario: Setting output voltage in adjustable LDO feedback divider where reference stability directly impacts regulation accuracy. IC Role / Device Role / Timing Role: Precision Zener element replacing internal bandgap reference to improve line/load regulation performance. Use Value: Low 7 Ω impedance minimizes error contribution from divider current mismatch, improving overall regulation to ±0.5%.	Use Scenario: Generating temperature-compensated bias current for RF amplifier stages operating across –40°C to +125°C ambient. IC Role / Device Role / Timing Role: Stable voltage source feeding constant-current generator circuitry with predictable thermal coefficient. Use Value: DO-35 glass package and –65°C to +200°C rating maintain V_Z drift <0.05%/°C, ensuring consistent bias point over full industrial range.

Low-Power Voltage Reference

Overvoltage Clamp

Use Scenario: Providing stable 7.79 V reference for ADC biasing and op-amp feedback networks in portable instrumentation.

IC Role / Device Role / Timing Role: Shunt voltage reference element establishing fixed DC potential independent of supply fluctuations.

Use Value: ±5% V_Z tolerance and 7 Ω impedance ensure <±10 mV output shift over 1–5 mA load range, preserving measurement accuracy.

Use Scenario: Protecting microcontroller I/O pins from transient overvoltage events exceeding 8.61 V in industrial control panels.

IC Role / Device Role / Timing Role: Reverse-biased clamping diode diverting surge current away from sensitive inputs during ESD or inductive kickback.

Use Value: 61 mA I_ZM rating and 1.2 V forward drop allow safe energy absorption without latch-up or permanent damage.

Linear Regulator Feedback

Temperature-Stable Bias Generator

Use Scenario: Setting output voltage in adjustable LDO feedback divider where reference stability directly impacts regulation accuracy.

IC Role / Device Role / Timing Role: Precision Zener element replacing internal bandgap reference to improve line/load regulation performance.

Use Value: Low 7 Ω impedance minimizes error contribution from divider current mismatch, improving overall regulation to ±0.5%.

Use Scenario: Generating temperature-compensated bias current for RF amplifier stages operating across –40°C to +125°C ambient.

IC Role / Device Role / Timing Role: Stable voltage source feeding constant-current generator circuitry with predictable thermal coefficient.

Use Value: DO-35 glass package and –65°C to +200°C rating maintain V_Z drift <0.05%/°C, ensuring consistent bias point over full industrial range.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
1N4738A (ON Semiconductor)	8.2 V nominal, ±5% tolerance, 1.0 Ω Z_Z @ 20 mA, DO-41 package	Higher power (1 W), lower impedance, but larger footprint and different thermal profile	Select when higher power margin or lower dynamic impedance is required; verify PCB pad compatibility with DO-41 vs DO-35.
BZX55-C7V5 (Vishay)	7.5 V nominal, ±5% tolerance, 15 Ω Z_Z @ 5 mA, DO-35 package	Near-identical form factor but higher impedance and 0.5 V lower nominal voltage	Choose for legacy BZX55 design reuse; confirm system-level tolerance budget accommodates 7.5 V vs 7.79 V nominal.

Compared with 1N5998B_T50A, the 1N4738A offers higher power and lower impedance but requires board rework for DO-41, while the BZX55-C7V5 matches the DO-35 footprint but trades 0.29 V lower nominal voltage and 2.1× higher impedance - impacting regulation precision in low-current references.

Availability

1N5998B_T50A 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 parametric consistency.

Supply support for 1N5998B_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, analog, and discrete devices before its acquisition by ON Semiconductor in 2016; its legacy Zener diodes remain widely deployed in industrial and automotive systems.

The 1N59xxB series was designed specifically for high-stability, low-power voltage reference and clamping applications where tight tolerance, low leakage, and wide temperature operation are mandatory - not general-purpose rectification.

FAQ

What is the nominal Zener voltage of the 1N5998B_T50A?

The 1N5998B_T50A has a nominal Zener voltage of 7.79 V, with a minimum of 7.79 V and maximum of 8.61 V at 5 mA test current, per the Fairchild datasheet Rev. C2. This value reflects the center of its ±5% tolerance band and defines its primary function as a precision shunt voltage reference in analog circuits.

What package type does the 1N5998B_T50A use?

The 1N5998B_T50A uses the DO-35 glass axial package, identified by a cathode color band and standardized lead spacing. This hermetically sealed package ensures long-term parameter stability and moisture resistance, making it suitable for industrial and automotive applications where environmental reliability is critical.

What is the maximum power dissipation for the 1N5998B_T50A?

The 1N5998B_T50A is rated for 500 mW power dissipation at lead temperature (T_L) ≤ 75°C, with a linear derating of 4.0 mW/°C above that temperature. This specification defines the thermal boundary for continuous operation in shunt regulator and clamping applications without exceeding junction temperature limits.

How much leakage current does the 1N5998B_T50A exhibit at 6.5 V?

The 1N5998B_T50A exhibits a maximum leakage current of 0.5 mA at 6.5 V reverse bias (V_R), as specified in the Fairchild datasheet. This low leakage supports energy-efficient operation in battery-powered systems and ensures minimal loading on upstream voltage sources in reference circuits.

What is the Zener impedance of the 1N5998B_T50A at its test current?

The 1N5998B_T50A has a Zener impedance (Z_Z) of 7 Ω at the specified test current of 5 mA. This low dynamic impedance ensures minimal voltage variation under changing load conditions, which is essential for maintaining accuracy in precision voltage reference and feedback applications.

1N5998B_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):: 8.2 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 7 Ohms

Current - Reverse Leakage @ Vr:: 500 nA @ 6.5 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

1N5998B_T50A FAQ

1.How can I place an order for 1N5998B_T50A through Aetrix?

Please submit a Request for Quotation (RFQ) for 1N5998B_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 1N5998B_T50A reliable?

The price and inventory of 1N5998B_T50A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5998B_T50A is usually 5 days.

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We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5998B_T50A transactions.

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4.How is shipping managed for 1N5998B_T50A?

1N5998B_T50A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1N5998B_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 1N5998B_T50A?

For technical support, including 1N5998B_T50A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5998B_T50A requirements.

6.How does Aetrix verify that 1N5998B_T50A is sourced from the original manufacturer or authorized distributors?

All 1N5998B_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 1N5998B_T50A meets industry standards.

7.What is the process for return or replacement of 1N5998B_T50A?

All 1N5998B_T50A units undergo pre-shipment inspection (PSI). If there is an issue with 1N5998B_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 1N5998B_T50A part is unused and in its original packaging.

Return procedure for 1N5998B_T50A:

1.Submit a request within 90 days.

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

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