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

Diodes Incorporated 1N5225B-T

Name: 1N5225B-T
Brand: Diodes Incorporated
SKU: 1N5225B-T
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 1N5225B-T

Manufacturer:: Diodes Incorporated

Category:: Single Zener Diodes

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

Datasheet:: 1N5225B-T.pdf

Description:: DIODE ZENER 3V 500MW DO35

Quantity:: RFQ Add To RFQ list

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Inventory:6,118

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Product details

Overview

1N5225B-T from Diodes Incorporated is a 3.0 V, ±5% tolerance, 500 mW surface-mount Zener diode in a hermetic DO-35 glass package, optimized for precision voltage regulation and reference applications in low-power analog circuits, power supply feedback paths, and overvoltage protection. It delivers 29 Ω dynamic impedance at 20 mA test current, -0.075 %/°C temperature coefficient, and 50 µA maximum reverse leakage at 1.0 V.

For engineers reviewing the 1N5225B-T datasheet, 1N5225B-T pinout, 1N5225B-T application, or 1N5225B-T equivalent, this part serves as a legacy discrete voltage reference requiring attention to obsolescence status, thermal derating above 75°C, RoHS-compliant lead finish, and direct replacement with MMSZ5225B for new designs.

Technical Context

This Zener diode operates in reverse breakdown mode with tightly controlled V_Z = 3.0 V (min 2.85 V, max 3.15 V) at I_ZT = 20 mA. Its -0.075 %/°C temperature coefficient ensures stable reference voltage across industrial temperature ranges (-65°C to +175°C).

The device uses an epitaxial construction for high stability and low noise, with a cathode band polarity marker and Sn96.5Ag3.5 solderable terminals meeting MIL-STD-202. Thermal resistance is 300 °C/W junction-to-ambient under specified lead conditions (9.5 mm length, T_L ≤ 75°C).

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	3.0 V nominal, ±5% tolerance - defines precise clamping/reference level in feedback or protection circuits
Power Dissipation (P_D)	500 mW - limits continuous operating current to ~167 mA at 3.0 V without forced cooling
Zener Impedance (Z_ZT)	29 Ω at 20 mA - determines regulation accuracy under load transients
Temperature Coefficient	-0.075 %/°C - enables predictable drift compensation in temperature-sensitive references
Reverse Leakage (I_R)	50 µA max at 1.0 V - ensures minimal quiescent current in high-impedance bias networks
Package	DO-35 glass - hermetic, surface-mount compatible, moisture sensitivity Level 1

Pinout & Package

DO-35 glass axial package with cathode band marking; two-terminal device with no internal circuitry beyond the Zener junction.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward conduction terminal / Zener cathode reference ground node	Connected to lower-potential side of regulated circuit; used as reference return path
Cathode	Zener breakdown terminal / voltage clamp input	Connected to higher-potential node needing regulation; marked by visible band

Key Features

Feature	Design Value
Hermetic glass package	Ensures long-term parameter stability and reliability in humid or corrosive environments
±5% V_Z tolerance	Reduces need for external trimming in cost-sensitive voltage reference designs
Lead-free, RoHS-compliant finish	Meets global environmental compliance requirements without compromising solderability
High stability epitaxial structure	Minimizes parameter drift over time and temperature versus diffused Zener alternatives

Applications

Power Supply Feedback

Overvoltage Protection

Use Scenario: Regulating output voltage in linear regulators or switching converter feedback loops.

IC Role / Device Role / Timing Role: Precision voltage reference providing stable setpoint for error amplifier comparison.

Use Value: Enables ±1% output regulation accuracy with minimal external components due to tight V_Z tolerance and low Z_ZT.

Use Scenario: Clamping transient surges on low-voltage signal or power rails.

IC Role / Device Role / Timing Role: Shunt protection element diverting excess current when rail exceeds 3.0 V.

Use Value: Limits peak voltage to 3.15 V (max) during ESD or load-dump events, protecting downstream CMOS inputs.

Reference Voltage Source

Current Source Biasing

Use Scenario: Generating stable bias voltages for op-amp comparators or ADC references.

IC Role / Device Role / Timing Role: Low-noise, temperature-compensated voltage source for analog subsystems.

Use Value: Delivers <10 ppm/°C drift over -40°C to +85°C, supporting 12-bit measurement accuracy.

Use Scenario: Setting constant current in LED driver or sensor excitation circuits.

IC Role / Device Role / Timing Role: Voltage reference defining current through series resistor (I = V_Z/R).

Use Value: Maintains ±0.75% current accuracy over temperature due to matched TC and low Z_ZT.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMSZ5225B	SMT SOD-123 package, same 3.0 V/±5%/500 mW specs, lower R_θJA (350 °C/W)	Designed for automated PCB assembly; no axial leads or manual tinning required	Select for new designs requiring RoHS-compliant, high-volume SMT manufacturability
1N4728A	3.3 V nominal, 1 W power rating, DO-41 package, ±5% tolerance	Higher power handling but looser TC (+0.055 %/°C) and larger footprint	Choose only if 3.3 V regulation and >500 mW dissipation are mandatory

Compared with MMSZ5225B and 1N4728A, the 1N5225B-T offers superior temperature stability and legacy compatibility in DO-35 form factor, but requires manual assembly and has been discontinued-MMSZ5225B is the recommended drop-in SMT replacement.

Availability

1N5225B-T is available at Aetrix Electronics and suitable for legacy repair, aerospace maintenance, industrial control retrofitting, and medical equipment service requiring stable component supply despite obsolescence status.

Supply support for 1N5225B-T 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, headquartered in Plano, Texas, with design and manufacturing operations across Asia and the Americas.

The 1N52xxB series belongs to Diodes' legacy Zener diode product line, engineered for general-purpose voltage regulation and reference applications where hermetic reliability and tight tolerance are prioritized over modern packaging.

FAQ

Is the 1N5225B-T still in active production?

No, Diodes Incorporated has officially discontinued the 1N5225B-T. It is marked "OBSOLETE – PART DISCONTINUED" in the DS18006 datasheet (Rev. 19-4, September 2019). Aetrix Electronics maintains limited legacy stock for service and repair use, but new designs should migrate to MMSZ5225B.

What is the maximum allowable junction temperature for continuous operation?

The absolute maximum junction temperature is +175°C, but continuous operation must respect the 500 mW power limit and thermal derating curve. At ambient temperatures above 75°C, power must be reduced linearly per the 300 °C/W R_θJA, with leads held at ≤75°C using 9.5 mm length.

Can the 1N5225B-T replace a 1N5226B in a circuit?

Only if the circuit tolerates a 0.3 V higher Zener voltage (3.3 V vs. 3.0 V) and its temperature coefficient (+0.070 %/°C vs. -0.075 %/°C). The 1N5226B has slightly lower Z_ZT (28 Ω), but both share identical power rating, package, and test current-electrical substitution requires validation of system-level regulation margin.

Does the DO-35 package support reflow soldering?

No-the DO-35 glass package is not rated for standard reflow profiles. Diodes Incorporated specifies hand-soldering per MIL-STD-202, Method 208, with localized heating and strict thermal limits. Reflow risks cracking the glass envelope or degrading Zener characteristics; wave or selective soldering is preferred for through-hole variants.

1N5225B-T Specifications

Product attributes: Attribute value

Manufacturer:: Diodes Incorporated

Series:: -

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

Packaging:: Tape & Reel (TR)

Product Status:: Obsolete

Voltage - Zener (Nom) (Vz):: 3 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 29 Ohms

Current - Reverse Leakage @ Vr:: 50 µA @ 1 V

Voltage - Forward (Vf) (Max) @ If:: 1.1 V @ 200 mA

Operating Temperature:: -65°C ~ 200°C

Grade:: -

Qualification:: -

Mounting Type:: Through Hole

Supplier Device Package:: DO-35

1N5225B-T FAQ

1.How can I place an order for 1N5225B-T through Aetrix?

Please submit a Request for Quotation (RFQ) for 1N5225B-T 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 1N5225B-T reliable?

The price and inventory of 1N5225B-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5225B-T is usually 5 days.

3.What payment methods are accepted for 1N5225B-T?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5225B-T transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 1N5225B-T?

1N5225B-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1N5225B-T 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 1N5225B-T?

For technical support, including 1N5225B-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5225B-T requirements.

6.How does Aetrix verify that 1N5225B-T is sourced from the original manufacturer or authorized distributors?

All 1N5225B-T 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 1N5225B-T meets industry standards.

7.What is the process for return or replacement of 1N5225B-T?

All 1N5225B-T units undergo pre-shipment inspection (PSI). If there is an issue with 1N5225B-T, 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 1N5225B-T part is unused and in its original packaging.

Return procedure for 1N5225B-T:

1.Submit a request within 90 days.

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

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