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

onsemi 1N5989B_T50R

Name: 1N5989B_T50R
Brand: onsemi
SKU: 1N5989B_T50R
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 1N5989B_T50R

Manufacturer:: onsemi

Category:: Single Zener Diodes

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

Datasheet:: 1N5989B_T50R.pdf

Description:: DIODE ZENER 3.6V 500MW DO35

Quantity:: RFQ Add To RFQ list

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Product details

Overview

1N5989B_T50R from Fairchild Semiconductor is a 3.6 V ±5% Zener diode in DO-35 glass package, rated for 500 mW power dissipation at TL ≤ 75°C with 4.0 mW/°C derating, 90 Ω dynamic impedance at 5 mA test current, and 15 μA leakage current at 1 V reverse bias - used for precision voltage reference and overvoltage protection in low-power analog circuits.

For engineers reviewing the 1N5989B_T50R datasheet, pinout, applications, or equivalent options, key selection criteria include zener voltage tolerance, thermal derating behavior, junction temperature range (–65°C to +200°C), and DO-35 mechanical compatibility in space-constrained PCB layouts.

Technical Context

This Zener diode operates in reverse breakdown mode with tightly controlled V_Z = 3.6 V (min 3.42 V, typ 3.6 V, max 3.78 V) at I_Z = 5 mA, exhibiting 90 Ω impedance under nominal bias and 2300 Ω knee impedance at I_ZK = 250 μA. Its 139 mA maximum zener current (I_ZM) is derived from the 500 mW power limit and actual V_Z.

The device uses a glass-passivated DO-35 axial package with cathode band marking, supports lead temperature-based thermal management up to 75°C, and maintains stable regulation across –65°C to +200°C operating and storage range - enabling use in automotive under-hood and industrial control environments.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	3.6 V ±5% at 5 mA - defines precise clamping threshold for 3.3 V rail stabilization
Power Dissipation (P_D)	500 mW @ T_L ≤ 75°C - sets maximum continuous power handling before thermal derating begins
Zener Impedance (Z_Z)	90 Ω @ 5 mA - determines output voltage stability under load variation in reference circuits
Leakage Current (I_R)	15 μA @ 1 V reverse - ensures minimal quiescent current draw in battery-powered sensing nodes
Max Zener Current (I_ZM)	139 mA - calculated from P_D/V_Z, defines absolute peak surge capability without damage
Operating Temp Range	–65°C to +200°C - supports deployment in extended-temperature industrial and automotive applications

Pinout & Package

DO-35 glass axial package with cathode indicated by color band; two-terminal device with anode and cathode leads. No polarity-sensitive mounting orientation required beyond standard axial diode placement.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward conduction terminal / Zener reference ground node	Connected to circuit ground or lower-potential rail when used in shunt regulation
Cathode	Reverse-biased breakdown terminal / regulated output node	Connected to voltage source input; delivers stable 3.6 V to downstream circuitry

Key Features

Feature	Design Value
±5% Zener voltage tolerance	Enables accurate 3.3 V rail monitoring without external trimming components
DO-35 glass encapsulation	Provides hermetic sealing and high reliability in humid or corrosive ambient conditions
Low knee impedance (2300 Ω @ 250 μA)	Ensures predictable turn-on behavior during transient overvoltage events
139 mA I_ZM rating	Supports short-duration surge suppression in ESD-coupled signal lines

Applications

3.3 V Power Rail Regulation	Microcontroller Reset Circuit
Use Scenario: Stabilizing 3.3 V supply in low-current sensor interface modules where LDO cost or footprint is prohibitive. IC Role / Device Role / Timing Role: Shunt voltage regulator providing passive reference point for analog front-end circuitry. Use Value: Delivers ±5% regulation accuracy without external feedback network or quiescent current overhead.	Use Scenario: Generating clean reset signal for ARM Cortex-M0 microcontrollers during brown-out conditions. IC Role / Device Role / Timing Role: Threshold detector that pulls reset line low until V_CC exceeds 3.42 V. Use Value: Eliminates need for dedicated reset IC while maintaining guaranteed 3.42–3.78 V activation window.
Industrial Sensor Signal Conditioning	ESD Protection Clamp
Use Scenario: Biasing op-amp input stages in 4–20 mA transmitter designs operating across –40°C to +85°C. IC Role / Device Role / Timing Role: Precision DC reference establishing common-mode voltage for differential amplifiers. Use Value: Maintains <±1% drift over full industrial temperature range due to low tempco of DO-35 Zener structure.	Use Scenario: Secondary clamping stage on RS-485 bus lines exposed to IEC 61000-4-2 Level 4 transients. IC Role / Device Role / Timing Role: Fast-acting voltage limiter absorbing residual energy after primary TVS conduction. Use Value: Limits clamped voltage to ≤3.78 V, protecting 3.3 V transceivers without adding capacitance to data lines.

3.3 V Power Rail Regulation

Microcontroller Reset Circuit

Use Scenario: Stabilizing 3.3 V supply in low-current sensor interface modules where LDO cost or footprint is prohibitive.

IC Role / Device Role / Timing Role: Shunt voltage regulator providing passive reference point for analog front-end circuitry.

Use Value: Delivers ±5% regulation accuracy without external feedback network or quiescent current overhead.

Use Scenario: Generating clean reset signal for ARM Cortex-M0 microcontrollers during brown-out conditions.

IC Role / Device Role / Timing Role: Threshold detector that pulls reset line low until V_CC exceeds 3.42 V.

Use Value: Eliminates need for dedicated reset IC while maintaining guaranteed 3.42–3.78 V activation window.

Industrial Sensor Signal Conditioning

ESD Protection Clamp

Use Scenario: Biasing op-amp input stages in 4–20 mA transmitter designs operating across –40°C to +85°C.

IC Role / Device Role / Timing Role: Precision DC reference establishing common-mode voltage for differential amplifiers.

Use Value: Maintains <±1% drift over full industrial temperature range due to low tempco of DO-35 Zener structure.

Use Scenario: Secondary clamping stage on RS-485 bus lines exposed to IEC 61000-4-2 Level 4 transients.

IC Role / Device Role / Timing Role: Fast-acting voltage limiter absorbing residual energy after primary TVS conduction.

Use Value: Limits clamped voltage to ≤3.78 V, protecting 3.3 V transceivers without adding capacitance to data lines.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
1N4728A (ON Semiconductor)	3.3 V ±5%, 1 W rating, DO-41 package - higher power but larger footprint and looser V_Z tolerance at low currents	Preferred for higher-power 3.3 V references requiring >500 mW headroom; unsuitable for DO-35 board space constraints	Select when thermal margin >150°C rise is needed; avoid if PCB real estate or 3.6 V exactness is critical
BZX55-C3V6 (Vishay)	3.6 V ±5%, 500 mW, DO-35 - identical electrical specs but tighter ZZ distribution (85 Ω typ) and RoHS-compliant glass passivation	Drop-in replacement where lead-free compliance or enhanced long-term Zener stability is mandated	Choose for new designs requiring RoHS-6 compliance or improved parametric consistency across production lots

Compared with 1N5989B_T50R, the 1N4728A offers greater power headroom but requires layout revision for DO-41, while BZX55-C3V6 matches form, fit, and function with superior process control - making it ideal for migration paths demanding zero hardware change.

Availability

1N5989B_T50R is available at Aetrix Electronics and suitable for 3.3 V power rail regulation, microcontroller reset circuits, and industrial sensor signal conditioning requiring stable component supply and long-lifecycle support.

Supply support for 1N5989B_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 devices before its acquisition by ON Semiconductor in 2016; its legacy Zener portfolio remains widely deployed in industrial and automotive systems.

The 1N5985B–1N6025B series was engineered for high-reliability voltage reference and clamping in harsh-environment applications, emphasizing tight V_Z tolerance, wide temperature operation, and robust glass-package construction.

FAQ

What is the exact Zener voltage range for 1N5989B_T50R at 5 mA test current?

The 1N5989B_T50R has a specified Zener voltage range of 3.42 V (minimum), 3.6 V (typical), and 3.78 V (maximum) at I_Z = 5 mA and T_A = 25°C, reflecting its ±5% tolerance grade. This range ensures predictable clamping behavior in 3.3 V system interfaces and aligns with JEDEC-standardized Zener families for interchangeability.

Does 1N5989B_T50R support operation above 100°C junction temperature?

No - the 1N5989B_T50R specifies an operating temperature range of –65°C to +200°C for both junction and storage, but its power derating curve begins at T_L = 75°C, reducing allowable dissipation by 4.0 mW/°C. Sustained operation above 100°C requires thermal modeling to ensure junction temperature stays within limits based on PCB copper area and airflow.

Can 1N5989B_T50R be used as a substitute for 1N4728A in a 3.3 V reference design?

No - the 1N5989B_T50R is rated for 3.6 V Zener voltage, whereas the 1N4728A is a 3.3 V device; substituting them would shift the regulated voltage by ~0.3 V, potentially violating microcontroller V_DD tolerance. Their DO-35 vs. DO-41 packages also prevent direct PCB replacement without layout modification.

What is the forward voltage drop of 1N5989B_T50R at 200 mA?

The forward voltage (V_F) of 1N5989B_T50R is specified as ≤1.2 V at I_F = 200 mA per the Fairchild datasheet. This parameter applies only during forward conduction and is relevant for polarity-protection or OR-ing configurations, not for normal Zener regulation operation.

How does the 2300 Ω knee impedance (Z_ZK) affect low-current regulation performance of 1N5989B_T50R?

The 2300 Ω knee impedance at I_ZK = 250 μA means the 1N5989B_T50R exhibits significant voltage droop below 1 mA bias current - resulting in poor regulation accuracy in ultra-low-power sleep modes. For stable sub-1 mA operation, supplemental bias current or alternative low-I_Z Zeners like BZX55-C3V6 should be considered.

1N5989B_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):: 3.6 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 90 Ohms

Current - Reverse Leakage @ Vr:: 15 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

1N5989B_T50R FAQ

1.How can I place an order for 1N5989B_T50R through Aetrix?

Please submit a Request for Quotation (RFQ) for 1N5989B_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 1N5989B_T50R reliable?

The price and inventory of 1N5989B_T50R are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5989B_T50R is usually 5 days.

3.What payment methods are accepted for 1N5989B_T50R?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5989B_T50R transactions.

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4.How is shipping managed for 1N5989B_T50R?

1N5989B_T50R orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1N5989B_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 1N5989B_T50R?

For technical support, including 1N5989B_T50R datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5989B_T50R requirements.

6.How does Aetrix verify that 1N5989B_T50R is sourced from the original manufacturer or authorized distributors?

All 1N5989B_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 1N5989B_T50R meets industry standards.

7.What is the process for return or replacement of 1N5989B_T50R?

All 1N5989B_T50R units undergo pre-shipment inspection (PSI). If there is an issue with 1N5989B_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 1N5989B_T50R part is unused and in its original packaging.

Return procedure for 1N5989B_T50R:

1.Submit a request within 90 days.

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

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