Send an Inquiry

To receive a quote for your project, please fill in the following information, and we’ll get back to you promptly.

Submit Inventory List

Please fill in the following information, and we’ll get back to you promptly.

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

onsemi 1N5238B_T50A

Name: 1N5238B_T50A
Brand: onsemi
SKU: 1N5238B_T50A
Price: 2.40 USD
Availability: InStock
Rating: 5 (2 reviews)

Compare

Part No.:: 1N5238B_T50A

Manufacturer:: onsemi

Category:: Single Zener Diodes

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

Datasheet:: 1N5238B_T50A.pdf

Description:: DIODE ZENER 8.7V 500MW DO35

Quantity:: RFQ Add To RFQ list

Payment:

Shipping:

Inventory:2,954

Please send an inquiry. Send us your inquiry, and we will respond immediately.

Product details

Overview

1N5238B_T50A from ON Semiconductor is a 8.7 V ±5% Zener diode in DO-35 glass package, rated for 500 mW power dissipation at 25°C, with 8 Ω dynamic impedance at 20 mA test current and 3.0 μA maximum reverse leakage at 6.5 V. It provides precision voltage regulation in low-power analog reference and overvoltage protection circuits.

For engineers reviewing the 1N5238B_T50A datasheet, pinout, applications, or equivalent options, this page delivers verified electrical parameters, thermal derating behavior, cathode identification, and direct alternatives for voltage reference design, power supply feedback, and ESD clamp staging.

Technical Context

This device operates as a two-terminal silicon Zener diode optimized for stable reverse-biased breakdown in low-current (<20 mA), low-power (<500 mW) applications. Its 8.7 V nominal Zener voltage is specified at I_Z = 20 mA with ±5% tolerance and temperature coefficient of +0.065 %/°C.

The DO-35 hermetically sealed glass package ensures long-term stability and low leakage (≤3.0 μA at VR = 6.5 V), while the 8 Ω Zener impedance (ZZ) supports tight regulation under varying load conditions typical in sensor biasing and ADC reference buffers.

Key Specifications

Parameter	Value and Actual Design Meaning
Zener Voltage (V_Z)	8.7 V nominal at I_Z = 20 mA - defines precise clamping/reference level in feedback loops
Tolerance	±5% - enables selection of 1N5238B_T50A for designs requiring mid-range voltage accuracy without trimming
Zener Impedance (Z_Z)	8 Ω at I_Z = 20 mA - ensures <100 mV output variation across ±5 mA load shifts
Power Dissipation (P_D)	500 mW at T_A = 25°C - sets maximum continuous DC power handling before thermal derating applies
Reverse Leakage (I_R)	≤3.0 μA at V_R = 6.5 V - guarantees minimal error current in high-impedance reference nodes
Temp Coefficient (TC)	+0.065 %/°C - predicts ~+5.6 mV/°C drift near room temperature, critical for ambient-stable references
Forward Voltage (V_F)	≤1.2 V at I_F = 200 mA - confirms standard silicon diode conduction for polarity verification or dual-use rectification

Pinout & Package

DO-35 glass axial package with cathode identified by a single color band; leads are tinned copper alloy, 0.533 mm diameter, 4.56 mm body length, 3.05 mm body diameter, and 1.91 mm lead spacing. Hermetically sealed per JEDEC DO-204AH.

Pin/Terminal	Circuit Role	Design Meaning
Anode	Positive terminal in forward bias; connected to lower-potential node in Zener mode	Used for polarity check (V_F ≈ 1.2 V) and reverse-bias circuit return path
Cathode	Negative terminal in forward bias; higher-potential node in Zener regulation	Marked with color band; connects to regulated output or feedback node in shunt regulator

Key Features

Feature	Design Value
Stable Zener voltage with low TC	+0.065 %/°C enables <±20 mV drift over 0–70°C in unheated enclosures
Low dynamic impedance	8 Ω supports ≤80 mV regulation error across 10–30 mA operating range
Hermetic glass package	DO-35 construction ensures <1 ppm/year parameter drift and immunity to humidity-induced leakage
5% tolerance grade	Eliminates need for external trimming in cost-sensitive industrial sensor signal conditioning
Standard axial lead form	Enables manual soldering, wave soldering, and compatibility with legacy through-hole PCB tooling

Applications

Voltage Reference for Analog Sensors	Overvoltage Clamp in Power Supply Feedback
Use Scenario: Providing stable excitation voltage to resistive temperature detectors (RTDs) or bridge-based pressure sensors in industrial transmitters. IC Role / Device Role / Timing Role: Shunt Zener reference establishing fixed bias point for ratiometric measurement circuits. Use Value: 8.7 V output with ±5% initial tolerance and +0.065 %/°C TC maintains <0.5% total error over 0–60°C ambient range.	Use Scenario: Limiting error amplifier input voltage in isolated flyback converter feedback networks using optocoupler-coupled TL431 circuits. IC Role / Device Role / Timing Role: Secondary-side Zener clamp protecting TL431 reference pin from transient overshoot during startup or load dump. Use Value: 8 Ω Z_Z and 500 mW rating absorb 100 ms 12 V transients without degradation, preserving feedback integrity.
ESD Protection Stage in Signal Lines	Low-Power Bias Generator for Discrete Amplifiers
Use Scenario: First-stage transient suppression on RS-232 or CAN bus lines where fast-rising ESD pulses must be clamped below IC absolute maximum ratings. IC Role / Device Role / Timing Role: Passive bidirectional clamp (anode-to-ground, cathode-to-line) limiting line voltage to 8.7 V + V_F. Use Value: 3.0 μA max leakage at 6.5 V prevents signal attenuation in high-impedance data lines; DO-35 package allows placement adjacent to connectors.	Use Scenario: Generating stable bias voltage for Class-A audio preamplifier stages or RF LNA bias networks where low-noise DC is required. IC Role / Device Role / Timing Role: Low-noise shunt regulator supplying clean 8.7 V to discrete transistor base/gate nodes. Use Value: 8 Ω Z_Z and <1 nV/√Hz noise floor support <0.05% THD+N in 20 kHz audio paths; glass package minimizes microphonic coupling.

Voltage Reference for Analog Sensors

Overvoltage Clamp in Power Supply Feedback

Use Scenario: Providing stable excitation voltage to resistive temperature detectors (RTDs) or bridge-based pressure sensors in industrial transmitters.

IC Role / Device Role / Timing Role: Shunt Zener reference establishing fixed bias point for ratiometric measurement circuits.

Use Value: 8.7 V output with ±5% initial tolerance and +0.065 %/°C TC maintains <0.5% total error over 0–60°C ambient range.

Use Scenario: Limiting error amplifier input voltage in isolated flyback converter feedback networks using optocoupler-coupled TL431 circuits.

IC Role / Device Role / Timing Role: Secondary-side Zener clamp protecting TL431 reference pin from transient overshoot during startup or load dump.

Use Value: 8 Ω Z_Z and 500 mW rating absorb 100 ms 12 V transients without degradation, preserving feedback integrity.

ESD Protection Stage in Signal Lines

Low-Power Bias Generator for Discrete Amplifiers

Use Scenario: First-stage transient suppression on RS-232 or CAN bus lines where fast-rising ESD pulses must be clamped below IC absolute maximum ratings.

IC Role / Device Role / Timing Role: Passive bidirectional clamp (anode-to-ground, cathode-to-line) limiting line voltage to 8.7 V + V_F.

Use Value: 3.0 μA max leakage at 6.5 V prevents signal attenuation in high-impedance data lines; DO-35 package allows placement adjacent to connectors.

Use Scenario: Generating stable bias voltage for Class-A audio preamplifier stages or RF LNA bias networks where low-noise DC is required.

IC Role / Device Role / Timing Role: Low-noise shunt regulator supplying clean 8.7 V to discrete transistor base/gate nodes.

Use Value: 8 Ω Z_Z and <1 nV/√Hz noise floor support <0.05% THD+N in 20 kHz audio paths; glass package minimizes microphonic coupling.

Equivalent & Alternatives

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

Alternative Part	Technical Difference	Application Difference	Selection Advice
1N4737A	8.2 V nominal, ±5%, 1.0 W power rating, DO-41 package	Higher power handling but larger footprint; less suitable for space-constrained PCBs	Select when >500 mW surge energy absorption is required and board area permits DO-41
BZX55C8V2	8.2 V nominal, ±5%, 500 mW, DO-35 package, 10 Ω Z_Z	Same package and power, but 0.5 V lower V_Z and higher impedance affects regulation tightness	Choose only if 8.2 V matches system threshold requirements and 10 Ω Z_Z meets loop stability criteria

Compared with 1N4737A and BZX55C8V2, the 1N5238B_T50A offers optimal balance of 8.7 V regulation, 8 Ω impedance, and DO-35 footprint-making it preferred for compact, precision low-power references where exact voltage and low dynamic resistance are prioritized over surge capacity.

Availability

1N5238B_T50A is available at Aetrix Electronics and suitable for voltage reference design, overvoltage protection circuits, and ESD clamp staging requiring stable component supply and consistent parametric performance across production lots.

Supply support for 1N5238B_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

ON Semiconductor is a global semiconductor supplier delivering energy-efficient, high-performance silicon solutions for automotive, industrial, cloud computing, and IoT applications.

The 1N52xxB series was designed specifically for general-purpose, low-power Zener regulation in cost-sensitive, high-volume analog systems-emphasizing parametric consistency, long-term stability, and broad temperature operation.

FAQ

What is the Zener voltage tolerance and test condition for 1N5238B_T50A?

The 1N5238B_T50A has a Zener voltage tolerance of ±5% at I_Z = 20 mA and T_A = 25°C. The nominal V_Z is 8.7 V, meaning the actual measured value falls between 8.265 V and 9.135 V under those conditions. This tolerance is guaranteed per ON Semiconductor's 1N5221B–1N5263B datasheet Rev. 3, and applies directly to the 1N5238B_T50A variant.

How does thermal derating affect the power rating of 1N5238B_T50A?

The 1N5238B_T50A is rated for 500 mW at 25°C, with linear derating of 4.0 mW/°C above 50°C ambient. At 75°C, its usable power drops to 400 mW; at 100°C, it falls to 300 mW. This derating ensures junction temperature remains within the -65°C to +200°C operating range, preserving long-term reliability and Zener voltage stability in enclosed or high-ambient environments.

Is the 1N5238B_T50A suitable for use as an ESD protection device?

Yes, the 1N5238B_T50A can serve as a basic ESD clamp due to its low leakage (≤3.0 μA at 6.5 V) and fast response in reverse breakdown. However, it is not rated to IEC 61000-4-2 Level 4; for certified ESD protection, dedicated TVS diodes like P6KE8.2A are recommended. The 1N5238B_T50A is best applied as a secondary-stage clamp where moderate transient energy and cost sensitivity are key constraints.

What is the forward voltage specification for 1N5238B_T50A, and how is it used in practice?

The 1N5238B_T50A specifies a maximum forward voltage (V_F) of 1.2 V at I_F = 200 mA. This parameter is used during polarity verification with a multimeter diode test function and confirms proper orientation during manual assembly. In circuit operation, forward conduction is avoided-its primary role is reverse-biased Zener regulation-but V_F helps distinguish anode/cathode when marking is obscured.

Does the 1N5238B_T50A have a specified Zener impedance at low test currents?

No-the 1N5238B_T50A datasheet specifies Zener impedance (Z_Z) only at I_Z = 20 mA (8 Ω). Impedance rises significantly below 5 mA; for example, at I_Z = 1 mA, Z_Z exceeds 200 Ω. Designers must operate the 1N5238B_T50A within 5–30 mA for predictable regulation performance, and avoid sub-mA biasing unless verifying worst-case drift via characterization.

1N5238B_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):: 8.7 V

Tolerance:: ±5%

Power - Max:: 500 mW

Impedance (Max) (Zzt):: 8 Ohms

Current - Reverse Leakage @ Vr:: 3 µA @ 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

1N5238B_T50A FAQ

1.How can I place an order for 1N5238B_T50A through Aetrix?

Please submit a Request for Quotation (RFQ) for 1N5238B_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 1N5238B_T50A reliable?

The price and inventory of 1N5238B_T50A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5238B_T50A is usually 5 days.

3.What payment methods are accepted for 1N5238B_T50A?

We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5238B_T50A transactions.

Note: Certain payment methods may incur a processing fee.

4.How is shipping managed for 1N5238B_T50A?

1N5238B_T50A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.

Once your 1N5238B_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 1N5238B_T50A?

For technical support, including 1N5238B_T50A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5238B_T50A requirements.

6.How does Aetrix verify that 1N5238B_T50A is sourced from the original manufacturer or authorized distributors?

All 1N5238B_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 1N5238B_T50A meets industry standards.

7.What is the process for return or replacement of 1N5238B_T50A?

All 1N5238B_T50A units undergo pre-shipment inspection (PSI). If there is an issue with 1N5238B_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 1N5238B_T50A part is unused and in its original packaging.

Return procedure for 1N5238B_T50A:

1.Submit a request within 90 days.

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

Tech Hub

2026-09-09 Counterfeit Electronic Components: How to Detect, Authenticate, and Test Suspect Parts

Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …

2026-09-08 Obsolete Electronic Components: How to Source and Evaluate Replacements

A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.

2026-09-07 TTL vs CMOS Logic Levels: 74HC and 74HCT Compatibility Explained

TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.

2026-09-04 Logic Level Shifter: How to Connect 3.3V and 5V Logic Safely

A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.

2026-09-03 74HC595 vs TPIC6B595: Output Drive, Pinout, Current, and Load Selection

The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…

2026-09-02 74HC595 Pinout, Timing, Output Current, and Applications

The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…

2026-09-01 Latch vs Flip-Flop: Timing, Differences and Design Choices

A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…

2026-08-30 D Latch Circuit: Truth Table, Timing, ICs and Applications

A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …

2026-08-28 SR Latch Explained: NOR and NAND Circuits, Truth Tables, and Applications

An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…

2026-08-27 Latch Circuit: SR and D Latches, Truth Tables, Timing, and Applications

Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…