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

Microchip Technology 1N5281B/TR

Name: 1N5281B/TR
Brand: Microchip Technology
SKU: 1N5281B/TR
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 1N5281B/TR

Manufacturer:: Microchip Technology

Category:: Single Zener Diodes

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

Datasheet:: 1N5281B/TR.pdf

Description:: DIODE ZENER 200V 500MW DO204AH

Quantity:: RFQ Add To RFQ list

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Inventory:5,071

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Product details

Overview

1N5281B/TR from Microsemi is a 200 V, ±5% tolerance, 500 mW glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for 0.65 mA test current and 2500 Ω dynamic impedance at 0.25 mA, operating from −65 °C to +175 °C. It serves as a precision voltage reference or overvoltage clamp in power supply feedback loops, sensor biasing, and industrial control circuits.

For engineers reviewing the 1N5281B/TR datasheet, 1N5281B/TR pinout, 1N5281B/TR application, or 1N5281B/TR equivalent, key selection criteria include its 200 V nominal Zener voltage, ±5% tolerance (B suffix), 2500 Ω Zener impedance at IZK = 0.25 mA, −65 °C to +175 °C operating range, and DO-35 hermetic glass package with cathode band marking.

Technical Context

This discrete Zener diode operates in reverse breakdown mode with a sharp knee characteristic verified by dual-point Zener impedance measurement per MicroNote 202. Its temperature coefficient of +0.110 %/°C (measured from 25 °C to 125 °C at rated IZT) ensures predictable drift across extended thermal ranges.

The device uses tin-lead or RoHS-compliant matte-tin plating, meets MIL-STD-750 Method 2026 solderability, and exhibits ESD insensitivity per MIL-STD-750 Method 1020. Its 0.2 g mass and axial-leaded DO-35 mechanical form support through-hole mounting on FR4 with defined thermal resistance (310 °C/W junction-to-ambient).

Key Specifications

Parameter	Value and Actual Design Meaning
Nominal Zener Voltage (V_Z)	200 V at I_ZT = 0.65 mA - defines stable regulation point for high-voltage reference applications
Tolerance	±5% (B suffix) - guarantees V_Z between 190 V and 210 V under specified test conditions
Power Dissipation	500 mW at 25 °C - sets maximum continuous DC power handling before thermal derating applies
Zener Impedance (Z_ZK)	2500 Ω at I_ZK = 0.25 mA - indicates dynamic resistance near knee; impacts regulation stability at low currents
Operating Temperature	−65 °C to +175 °C - enables use in aerospace, downhole, and military environments without derating
Thermal Resistance	310 °C/W junction-to-ambient on FR4 - determines temperature rise under load; requires copper pad design per spec
Reverse Leakage (I_R)	10 μA max at V_R = 160 V - defines minimum holding voltage before conduction; critical for standby leakage budgets

Pinout & Package

Hermetically sealed DO-35 (DO-204AH) glass axial-lead package with cathode indicated by a single black band; leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 Method 2026. Mounting requires 3/8″ (10 mm) lead length from body for rated thermal performance.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Non-banded end	Connected to lower-potential node; reverse-biased during Zener operation
Cathode	Banded end	Connected to higher-potential node; defines regulated output voltage reference point

Key Features

Feature	Design Value
JEDEC-registered 1N52xx series	Ensures standardized electrical behavior and interchangeability across qualified suppliers
Hermetic glass DO-35 construction	Provides long-term reliability and moisture resistance in harsh environments
Inherent radiation hardness	Validated per MicroNote 050 for TID tolerance - suitable for space-qualified systems
Nonsensitive to ESD	Withstands >4 kV HBM per MIL-STD-750 Method 1020 - eliminates need for external protection in handling
RoHS-compliant option (e3 suffix)	Enables compliance with environmental directives without sacrificing electrical or thermal performance

Applications

High-Voltage Power Supply Feedback	Industrial Sensor Biasing
Use Scenario: Regulating output voltage in flyback or forward converter feedback networks where primary-side sensing requires ≥150 V reference stability. IC Role / Device Role / Timing Role: Zener reference element providing precise 200 V threshold to optocoupler input or TL431 shunt regulator. Use Value: Maintains ±5% output regulation over −40 °C to +125 °C ambient with <2500 Ω dynamic impedance limiting error contribution.	Use Scenario: Providing stable excitation voltage to piezoresistive pressure sensors or RTD bridges in oil & gas downhole tools. IC Role / Device Role / Timing Role: High-voltage bias source delivering fixed 200 V to sensor Wheatstone bridge arms. Use Value: Enables accurate ratiometric measurements over −65 °C to +175 °C due to guaranteed tempco of +0.110 %/°C and hermetic sealing.
Military Voltage Clamping	Aerospace Overvoltage Protection
Use Scenario: Protecting analog front-end inputs in MIL-PRF-19500 screened systems against transients up to 250 V. IC Role / Device Role / Timing Role: Transient voltage suppressor clamping rail voltage to safe levels during ESD or surge events. Use Value: Delivers reliable clamping with 10 μA max leakage at 160 V and no parameter shift after MIL-STD-750 screening.	Use Scenario: Safeguarding avionics power rails exposed to lightning-induced surges in aircraft power distribution units. IC Role / Device Role / Timing Role: Primary Zener clamp absorbing energy during 100 ns–1 μs transients while maintaining low capacitance. Use Value: Minimal capacitance (typ. <2 pF per Figure 2) preserves signal integrity in high-frequency power monitoring circuits.

High-Voltage Power Supply Feedback

Industrial Sensor Biasing

Use Scenario: Regulating output voltage in flyback or forward converter feedback networks where primary-side sensing requires ≥150 V reference stability.

IC Role / Device Role / Timing Role: Zener reference element providing precise 200 V threshold to optocoupler input or TL431 shunt regulator.

Use Value: Maintains ±5% output regulation over −40 °C to +125 °C ambient with <2500 Ω dynamic impedance limiting error contribution.

Use Scenario: Providing stable excitation voltage to piezoresistive pressure sensors or RTD bridges in oil & gas downhole tools.

IC Role / Device Role / Timing Role: High-voltage bias source delivering fixed 200 V to sensor Wheatstone bridge arms.

Use Value: Enables accurate ratiometric measurements over −65 °C to +175 °C due to guaranteed tempco of +0.110 %/°C and hermetic sealing.

Military Voltage Clamping

Aerospace Overvoltage Protection

Use Scenario: Protecting analog front-end inputs in MIL-PRF-19500 screened systems against transients up to 250 V.

IC Role / Device Role / Timing Role: Transient voltage suppressor clamping rail voltage to safe levels during ESD or surge events.

Use Value: Delivers reliable clamping with 10 μA max leakage at 160 V and no parameter shift after MIL-STD-750 screening.

Use Scenario: Safeguarding avionics power rails exposed to lightning-induced surges in aircraft power distribution units.

IC Role / Device Role / Timing Role: Primary Zener clamp absorbing energy during 100 ns–1 μs transients while maintaining low capacitance.

Use Value: Minimal capacitance (typ. <2 pF per Figure 2) preserves signal integrity in high-frequency power monitoring circuits.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
1N5281B (no TR)	Identical electrical specs and DO-35 package; differs only in packaging - bulk vs. tape-and-reel	No functional difference; TR version supports automated SMT placement with EIA-296 compliant carrier tape	Select 1N5281B/TR when using pick-and-place equipment; choose bulk 1N5281B for manual or wave-solder assembly
MMBZ5281B (SOT-23)	Same 200 V/±5%/500 mW rating but in surface-mount SOT-23 package; higher thermal resistance (400 °C/W)	Used where board space is constrained and reflow compatibility is required; unsuitable for high-temp through-hole designs	Choose MMBZ5281B only if footprint reduction and reflow process justify trade-off in thermal performance and ruggedness

Compared with 1N5281B/TR, the bulk 1N5281B offers identical performance with manual handling flexibility, while MMBZ5281B trades hermetic glass robustness and thermal capability for SMT compatibility - making 1N5281B/TR optimal for high-reliability through-hole applications demanding radiation hardness and wide temperature operation.

Availability

1N5281B/TR is available at Aetrix Electronics and suitable for high-voltage power supply feedback, industrial sensor biasing, military voltage clamping, and aerospace overvoltage protection requiring stable component supply across extended temperature and radiation environments.

Supply support for 1N5281B/TR 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

Microsemi (now part of Microchip Technology) is a U.S.-based semiconductor company specializing in high-reliability, radiation-hardened, and high-voltage analog components for aerospace, defense, and industrial markets.

The 1N52xx series was designed specifically for precision voltage regulation in mission-critical systems where long-term stability, extreme temperature operation, and hermetic reliability are mandatory - not general-purpose consumer use.

FAQ

What is the Zener voltage tolerance for 1N5281B/TR?

The "B" suffix in 1N5281B/TR specifies a ±5% tolerance on the nominal 200 V Zener voltage, meaning the actual measured V_Z at I_ZT = 0.65 mA falls between 190 V and 210 V. This tolerance is guaranteed per JEDEC registration and verified during 100% testing, distinguishing it from non-suffixed or "A"-suffixed variants with looser limits.

Does 1N5281B/TR require derating above 25 °C?

Yes, 1N5281B/TR must be derated linearly above 25 °C ambient per Figure 1: power dissipation decreases from 500 mW at 25 °C to zero at 175 °C, yielding a derating slope of 3.45 mW/°C. When mounted on FR4 with specified copper pads, thermal resistance is 310 °C/W - so at 100 °C ambient, max allowable power drops to ~254 mW.

What does the "TR" suffix indicate in 1N5281B/TR?

"TR" denotes tape-and-reel packaging per EIA-296 standard, enabling automated pick-and-place assembly. The device itself is electrically and mechanically identical to 1N5281B in bulk packaging. No parameter differences exist - only logistics and handling format change, supporting high-volume manufacturing throughput.

Is 1N5281B/TR radiation hardened?

Yes, 1N5281B/TR is inherently radiation hard per MicroNote 050, with total ionizing dose (TID) tolerance validated for high-reliability applications. This property stems from its hermetic DO-35 glass construction and silicon process - not an added screening option - making it suitable for space and nuclear instrumentation without additional qualification.

Can 1N5281B/TR replace 1N5281A/TR in a design?

No - 1N5281B/TR has ±5% tolerance while 1N5281A/TR has ±10%, resulting in a wider V_Z spread (180–220 V vs. 190–210 V). Substituting without circuit review risks out-of-spec regulation, especially in tight-loop feedback or precision biasing. The B-suffix version also has tighter test limits on I_R, Z_ZK, and αV_Z, so direct replacement requires validation.

1N5281B/TR Specifications

Product attributes: Attribute value

Manufacturer:: Microchip Technology

Series:: -

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

Packaging:: Tape & Reel (TR)

Product Status:: Active

Voltage - Zener (Nom) (Vz):: 200 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 2500 Ohms

Current - Reverse Leakage @ Vr:: 100 nA @ 152 V

Voltage - Forward (Vf) (Max) @ If:: 1.5 V @ 200 mA

Operating Temperature:: -65°C ~ 175°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: DO-204AH (DO-35)

1N5281B/TR FAQ

1.How can I place an order for 1N5281B/TR through Aetrix?

Please submit a Request for Quotation (RFQ) for 1N5281B/TR 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 1N5281B/TR reliable?

The price and inventory of 1N5281B/TR are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5281B/TR is usually 5 days.

3.What payment methods are accepted for 1N5281B/TR?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5281B/TR transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 1N5281B/TR?

1N5281B/TR orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1N5281B/TR 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 1N5281B/TR?

For technical support, including 1N5281B/TR datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5281B/TR requirements.

6.How does Aetrix verify that 1N5281B/TR is sourced from the original manufacturer or authorized distributors?

All 1N5281B/TR 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 1N5281B/TR meets industry standards.

7.What is the process for return or replacement of 1N5281B/TR?

All 1N5281B/TR units undergo pre-shipment inspection (PSI). If there is an issue with 1N5281B/TR, 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 1N5281B/TR part is unused and in its original packaging.

Return procedure for 1N5281B/TR:

1.Submit a request within 90 days.

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

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