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

Diodes Incorporated 1N5243B-T

Name: 1N5243B-T
Brand: Diodes Incorporated
SKU: 1N5243B-T
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

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Part No.:: 1N5243B-T

Manufacturer:: Diodes Incorporated

Category:: Single Zener Diodes

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

Datasheet:: 1N5243B-T.pdf

Description:: DIODE ZENER 13V 500MW DO35

Quantity:: RFQ Add To RFQ list

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Inventory:4,140

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Product details

Overview

1N5243B-T from Diodes Incorporated is a 13V, ±5% tolerance, 500mW hermetic glass-encapsulated Zener diode in DO-35 package, rated for 9.5mA test current and 13Ω dynamic impedance at 9.5mA, used for precision voltage reference and overvoltage protection in low-power analog circuits.

For engineers reviewing the 1N5243B-T datasheet, 1N5243B-T pinout, 1N5243B-T application, or 1N5243B-T equivalent, key selection factors include its 13V nominal Zener voltage with ±5% tolerance, 13Ω Zener impedance at 9.5mA, 0.5µA maximum reverse leakage at 9.9V, +0.079%/°C temperature coefficient, and DO-35 glass package with cathode band polarity marking.

Technical Context

This discrete Zener diode operates in reverse breakdown to maintain stable voltage across its terminals under varying load and temperature conditions. Its 13V nominal Zener voltage is specified at 9.5mA test current with ±5% tolerance, and it exhibits a positive temperature coefficient of +0.079%/°C - indicating voltage increases with rising junction temperature.

The device delivers 500mW power dissipation capability when leads are maintained at ≤75°C (9.5mm lead length), with thermal resistance of 300°C/W junction-to-ambient. Its hermetic glass DO-35 package ensures long-term stability and moisture resistance per J-STD-020 Level 1.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	13V nominal, 12.35–13.65V range at 9.5mA - defines stable regulation point for reference or clamp applications
Power Dissipation (P_D)	500mW - sets maximum continuous reverse power handling before thermal runaway
Zener Impedance (Z_ZT)	13Ω at 9.5mA - determines output voltage variation under load current changes
Reverse Leakage (I_R)	0.5µA max at 9.9V - indicates low standby current in clamping or biasing roles
Temperature Coefficient	+0.079%/°C - quantifies voltage drift per degree Celsius rise in junction temperature
Package	DO-35 glass case - provides hermetic sealing, high reliability, and surface-mount compatibility

Pinout & Package

DO-35 glass axial package with cathode band marking; two-terminal device with no internal complexity - anode and cathode defined by physical band orientation.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Forward conduction terminal / Zener cathode reference ground	Connected to circuit ground or lower potential node in shunt regulation
Cathode	Reverse breakdown terminal / Zener voltage output	Connected to regulated node; voltage referenced to anode at 13V ±5%

Key Features

Feature	Design Value
Hermetic glass encapsulation	Ensures long-term parameter stability and immunity to humidity-induced degradation
±5% Zener voltage tolerance	Enables predictable regulation without post-manufacture trimming in cost-sensitive designs
Lead-free Sn96.5Ag3.5 finish	Complies with RoHS 2/3 directives while maintaining solderability per MIL-STD-202
Low 0.5µA reverse leakage at 9.9V	Minimizes quiescent current draw in battery-powered or low-power reference circuits

Applications

Power Supply Reference

Overvoltage Clamp

Use Scenario: Providing stable 13V reference for linear regulator feedback or ADC reference buffer.

IC Role / Device Role / Timing Role: Shunt voltage reference element establishing precise DC bias point.

Use Value: Delivers 13V ±5% with 13Ω dynamic impedance, enabling <±10mV regulation error under 1mA load variation.

Use Scenario: Protecting microcontroller I/O pins from transient overvoltage events exceeding 13V.

IC Role / Device Role / Timing Role: Passive voltage clamp limiting input voltage to safe threshold.

Use Value: Activates at 12.35V minimum, clamping within 100ns to limit stress on downstream CMOS inputs.

Current Source Bias

Signal Level Shifting

Use Scenario: Generating constant current for LED bias or op-amp input stage tail current.

IC Role / Device Role / Timing Role: Voltage-controlled current source via series resistor and fixed Zener drop.

Use Value: Enables 1mA current source with <2% drift over -40°C to +85°C using 12kΩ series resistor.

Use Scenario: Translating 3.3V logic signals to 13V interface levels in mixed-voltage systems.

IC Role / Device Role / Timing Role: DC level translator establishing offset between logic domains.

Use Value: Adds fixed 13V DC offset with minimal signal distortion due to low 13Ω Zener impedance.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
MMSZ5243B	Surface-mount SOD-123 package; same 13V ±5%, but 350mW P_D, 15Ω Z_ZT	Lower power rating and different thermal profile; requires PCB layout revision	Preferred for new SMT designs where board space and automated assembly are priorities
1N4742A	DO-41 package; 12V nominal, ±5%, 1W P_D, 9Ω Z_ZT at 21mA	Higher power, lower impedance, different voltage - not direct replacement without circuit recalculations	Consider only when higher power dissipation or tighter regulation is required and 12V suffices

Compared with MMSZ5243B and 1N4742A, the 1N5243B-T offers legacy through-hole compatibility, hermetic reliability, and optimized 13V regulation at 9.5mA - making it suitable for repair, legacy industrial control, and low-drift analog reference use cases where DO-35 mounting is retained.

Availability

1N5243B-T is available at Aetrix Electronics and suitable for power supply reference, overvoltage clamp, and current source bias applications requiring stable component supply and long-lifecycle support for industrial maintenance and legacy system repair.

Supply support for 1N5243B-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, specializing in high-reliability components for industrial, computing, and consumer markets.

The 1N52xxB series belongs to Diodes' legacy Zener diode product line, designed specifically for precision voltage regulation and protection in cost-sensitive, through-hole mounted analog subsystems.

FAQ

What is the maximum continuous power dissipation for 1N5243B-T?

The 1N5243B-T is rated for 500mW power dissipation when leads are held at ≤75°C with 9.5mm lead length. Derating begins above 75°C at 1.67mW/°C based on its 300°C/W thermal resistance. Exceeding this limit risks irreversible parametric shift or catastrophic failure.

How does the +0.079%/°C temperature coefficient affect circuit performance?

A +0.079%/°C coefficient means the Zener voltage increases by approximately 10.3mV per °C rise in junction temperature. Over a -40°C to +125°C range, this results in ~1.7V total drift - critical for precision references but acceptable for general-purpose clamping where absolute accuracy is secondary to threshold consistency.

Is 1N5243B-T RoHS compliant?

Yes - the 1N5243B-T features a lead-free Sn96.5Ag3.5 terminal finish and complies with EU RoHS 2 (2011/65/EU) and RoHS 3 (2015/863/EU) directives, including all applicable exemptions. Full compliance documentation is available via Diodes Incorporated's quality portal.

Why is the 1N5243B-T marked as obsolete, and what should designers do?

Diodes Incorporated has discontinued the 1N5243B-T in favor of the SMT MMSZ5243B. However, Aetrix Electronics maintains active inventory and traceable sourcing for legacy repair and maintenance. For new designs, migration to MMSZ5243B is recommended unless DO-35 mounting or hermetic reliability is mandatory.

1N5243B-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):: 13 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 13 Ohms

Current - Reverse Leakage @ Vr:: 500 nA @ 9.9 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

1N5243B-T FAQ

1.How can I place an order for 1N5243B-T through Aetrix?

Please submit a Request for Quotation (RFQ) for 1N5243B-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 1N5243B-T reliable?

The price and inventory of 1N5243B-T are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5243B-T is usually 5 days.

3.What payment methods are accepted for 1N5243B-T?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5243B-T transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 1N5243B-T?

1N5243B-T orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1N5243B-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 1N5243B-T?

For technical support, including 1N5243B-T datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5243B-T requirements.

6.How does Aetrix verify that 1N5243B-T is sourced from the original manufacturer or authorized distributors?

All 1N5243B-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 1N5243B-T meets industry standards.

7.What is the process for return or replacement of 1N5243B-T?

All 1N5243B-T units undergo pre-shipment inspection (PSI). If there is an issue with 1N5243B-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 1N5243B-T part is unused and in its original packaging.

Return procedure for 1N5243B-T:

1.Submit a request within 90 days.

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

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