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Microchip Technology 1N5238B
- Part No.:
- 1N5238B
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5238B.pdf
- Description:
- DIODE ZENER 8.7V 500MW DO204AH
- Quantity:
- Payment:
- Shipping:
Inventory:3,953
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Product details
Overview
1N5238B from Microsemi is a 500 mW glass axial-lead Zener diode with nominal Zener voltage of 8.7 V, ±5% tolerance (B suffix), 20 mA test current, and 8.0 Ω maximum Zener impedance at IZK = 0.25 mA. It operates from −65 °C to +175 °C and regulates voltage in low-power reference and protection circuits.
For engineers reviewing the 1N5238B datasheet, 1N5238B pinout, 1N5238B application, or 1N5238B equivalent, this part serves as a precision voltage reference in analog power supplies, overvoltage clamping in sensor interfaces, and bias stabilization in discrete amplifier stages - all requiring stable regulation under varying temperature and load conditions.
Technical Context
The 1N5238B functions as a two-terminal reverse-biased voltage regulator, maintaining 8.7 V across its terminals when reverse current exceeds the knee threshold (IZK = 0.25 mA). Its DO-35 glass package provides hermetic sealing and inherent radiation hardness per MicroNote 050.
It exhibits a positive temperature coefficient of +0.065 %/°C (measured from 25 °C to 125 °C at rated IZT), low junction-to-lead thermal resistance (250 °C/W), and minimal capacitance (<2.5 pF typical at VR = 0 V), enabling stable performance in high-frequency noise suppression and precision DC references.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 8.7 V at 20 mA - defines regulated output level for reference and clamp circuits |
| Zener Tolerance | ±5% (B suffix) - ensures predictable voltage window without post-selection |
| Power Dissipation | 500 mW at 25 °C - sets maximum continuous power handling on FR4 with standard layout |
| Zener Impedance | 8.0 Ω max at IZK = 0.25 mA - determines regulation stiffness under light-load transients |
| Operating Temperature | −65 °C to +175 °C - supports deployment in automotive under-hood and industrial control environments |
| Forward Voltage | ≤1.5 V at 200 mA - confirms standard silicon PN junction behavior for forward conduction checks |
| Temp. Coefficient αVZ | +0.065 %/°C - quantifies drift magnitude for temperature-compensated reference designs |
Pinout & Package
DO-35 (DO-204AH) glass axial-leaded package with cathode indicated by color band; leads are tin-lead or RoHS-compliant matte-tin plated, solderable per MIL-STD-750 Method 2026.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Non-banded end | Connected to lower-potential node during Zener operation; used for forward-bias verification |
| Cathode | Banded end | Connected to higher-potential node; carries regulated voltage output in reverse-bias configuration |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered Zener | Complies with industry-standard 1N52xxB specifications for interchangeability and test methodology |
| Radiation-hardened construction | Inherently radiation tolerant per MicroNote 050 - suitable for aerospace and defense systems |
| ESD-insensitive design | Passes MIL-STD-750 Method 1020 - eliminates need for external ESD protection in handling |
| Low dynamic capacitance | Typical <2.5 pF at 0 V - minimizes signal coupling in RF-adjacent or high-speed switching nodes |
| Hermetic glass seal | Prevents moisture ingress and long-term parameter drift in humid or corrosive environments |
Applications
| Industrial Power Monitoring | Automotive Sensor Signal Conditioning |
|---|---|
Use Scenario: Monitoring 12 V battery rail in PLC I/O modules with ±10% variation tolerance. IC Role / Device Role / Timing Role: Zener reference for comparator threshold setting and ADC input scaling. Use Value: Maintains 8.7 V reference stability across −40 °C to +85 °C ambient, enabling accurate fault detection without calibration drift. | Use Scenario: Clamping transient spikes on oxygen sensor analog outputs exposed to ignition noise. IC Role / Device Role / Timing Role: Reverse-biased shunt protector limiting voltage to ≤9.1 V during load-dump events. Use Value: Absorbs up to 500 mW surge energy without degradation, preserving downstream op-amp integrity per AEC-Q200 stress profiles. |
| Medical Instrument Biasing | Test Equipment Reference Source |
Use Scenario: Providing stable bias for photodiode transimpedance amplifiers in portable pulse oximeters. IC Role / Device Role / Timing Role: Low-noise DC reference establishing virtual ground and gain-setting node. Use Value: Delivers <2.5 pF capacitance and <8 Ω dynamic impedance, minimizing phase shift and settling time in 100 kHz bandwidth paths. | Use Scenario: Calibrating multimeter front-end attenuators requiring traceable 8.7 V reference points. IC Role / Device Role / Timing Role: Primary voltage standard in self-test and auto-zero subcircuits. Use Value: ±5% initial tolerance and +0.065 %/°C TC enable 0.1% absolute accuracy after single-point room-temp calibration. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4738A | Same 8.2 V nominal voltage but ±5% tolerance; 1.0 W power rating; DO-41 package | Higher power dissipation enables use in higher-current shunt regulators; larger DO-41 footprint requires PCB redesign | Select when >500 mW continuous dissipation is required and board space allows larger axial package |
| BZX55-C8V2 | 8.2 V nominal, ±5% tolerance; 500 mW rating; DO-35 package; tighter production lot control | Lower Zener impedance (7 Ω typ.) and improved tempco consistency; RoHS-only availability | Prefer for new designs targeting modern compliance and tighter parametric spread, especially in consumer-grade instrumentation |
Compared with 1N4738A and BZX55-C8V2, the 1N5238B offers JEDEC-registered legacy compatibility, radiation hardness, and proven reliability in extended-temperature industrial deployments - making it optimal where qualification continuity and environmental robustness outweigh minor voltage offset or impedance differences.
Availability
1N5238B is available at Aetrix Electronics and suitable for industrial power monitoring, automotive sensor signal conditioning, and medical instrument biasing requiring stable component supply across extended temperature ranges and long product lifecycles.
Supply support for 1N5238B 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 analog, mixed-signal, and radiation-hardened components for aerospace, defense, and industrial markets.
The 1N52xxB series was designed for precision voltage regulation in mission-critical systems where long-term stability, wide temperature operation, and environmental resilience are mandatory - not just general-purpose clamping.
FAQ
What is the nominal Zener voltage and tolerance of the 1N5238B?
The 1N5238B has a nominal Zener voltage of 8.7 V with a guaranteed tolerance of ±5%, as indicated by the "B" suffix per JEDEC specification. This tolerance applies at 20 mA test current and 25 °C ambient temperature, and is validated across the full operating temperature range of −65 °C to +175 °C per Microsemi's published electrical characteristics table.
What package type and marking does the 1N5238B use?
The 1N5238B uses the DO-35 (DO-204AH) glass axial-leaded package with cathode identified by a single color band. The device is marked with its full part number "1N5238B" on the glass body, and features tin-lead or RoHS-compliant matte-tin plating compliant with MIL-STD-750 Method 2026.
How does the 1N5238B perform under elevated temperature conditions?
The 1N5238B maintains specified regulation performance from −65 °C to +175 °C. Its Zener voltage exhibits a +0.065 %/°C temperature coefficient measured between 25 °C and 125 °C at rated test current, and its power dissipation derates linearly above 50 °C lead temperature per Figure 1 in the Microsemi datasheet - ensuring predictable behavior in under-hood or industrial enclosure environments.
Is the 1N5238B suitable for high-reliability or radiation-exposed applications?
Yes, the 1N5238B is inherently radiation-hardened per MicroNote 050 and qualified to MIL-PRF-19500 screening levels (e.g., JANTXV) when ordered with appropriate prefixes. Its hermetically sealed DO-35 glass construction and ESD insensitivity (MIL-STD-750 Method 1020) make it suitable for aerospace, defense, and nuclear instrumentation applications where parametric stability under ionizing radiation is required.
What is the maximum Zener impedance of the 1N5238B and at what condition is it specified?
The 1N5238B has a maximum Zener impedance (ZZK) of 8.0 Ω, specified at IZK = 0.25 mA - the knee current where regulation begins. This value reflects dynamic impedance near the breakdown onset and directly impacts regulation accuracy under light-load or transient conditions, such as in precision reference divider networks or low-current clamp circuits.
1N5238B Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- DO-204AH, DO-35, Axial
- Packaging:
- Bulk
- Product Status:
- Active
- 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:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 175°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- DO-204AH (DO-35)
1N5238B FAQ
1.How can I place an order for 1N5238B through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5238B 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 reliable?
The price and inventory of 1N5238B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5238B is usually 5 days.
3.What payment methods are accepted for 1N5238B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5238B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5238B?
1N5238B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5238B 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?
For technical support, including 1N5238B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5238B requirements.
6.How does Aetrix verify that 1N5238B is sourced from the original manufacturer or authorized distributors?
All 1N5238B 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 meets industry standards.
7.What is the process for return or replacement of 1N5238B?
All 1N5238B units undergo pre-shipment inspection (PSI). If there is an issue with 1N5238B, 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 part is unused and in its original packaging.
Return procedure for 1N5238B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5238B Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
-
BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
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