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Microchip Technology 1N5237B
- Part No.:
- 1N5237B
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5237B.pdf
- Description:
- DIODE ZENER 8.2V 500MW DO204AH
- Quantity:
- Payment:
- Shipping:
Inventory:8,613
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Product details
Overview
1N5237B from Microsemi is a 500 mW, 8.2 V ±5% glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for -65°C to +175°C operation, with 8 Ω zener impedance at 20 mA test current and 3.0 μA max reverse leakage at 6.2 V. It serves as a precision voltage reference or shunt regulator in low-power analog circuits, power supply feedback loops, and overvoltage protection.
For engineers reviewing the 1N5237B datasheet, 1N5237B pinout, 1N5237B application, or 1N5237B equivalent, key selection criteria include its 8.2 V nominal zener voltage, ±5% tolerance (B suffix), 500 mW power rating at 25°C, DO-35 mechanical form factor, and temperature coefficient of +0.062 %/°C - all critical for stable regulation under varying thermal and load conditions.
Technical Context
The 1N5237B operates as a silicon planar Zener diode with sharp breakdown knee, validated by dual-point zener impedance measurement (ZZT at IZT and ZZK at 0.25 mA). Its regulation relies on controlled avalanche and Zener mechanisms depending on voltage range, with dominant Zener behavior below 5.6 V and mixed/avalanche above - confirmed by its +0.062 %/°C tempco.
It is designed for DC or low-frequency AC regulation only, with minimal junction capacitance (<2.0 pF typical per Figure 2), nonsensitive to ESD (MIL-STD-750 Method 1020), and radiation-hardened per MicroNote 050. Thermal resistance is 250 °C/W junction-to-lead (3/8" lead length) and 310 °C/W junction-to-ambient on FR4.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 8.2 V @ 20 mA - defines regulated output voltage under standard test condition |
| Zener Impedance | 8 Ω @ 20 mA - indicates low dynamic resistance for stable regulation under load variation |
| Power Dissipation | 500 mW at 25°C - sets maximum continuous DC power before thermal derating applies |
| Reverse Leakage | 3.0 μA max @ 6.2 V - ensures minimal quiescent current in standby or high-impedance bias networks |
| Tempco (αVZ) | +0.062 %/°C - quantifies voltage drift with temperature; enables compensation in precision references |
| Operating Temp | -65°C to +175°C - supports extended industrial, aerospace, and downhole applications |
| Forward Voltage | 1.5 V max @ 200 mA - defines conduction threshold when used in forward-biased clamping |
Pinout & Package
DO-35 (DO-204AH) hermetically sealed 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 side during Zener operation; forward conduction path |
| Cathode | Banded end | Connected to higher potential side during Zener regulation; defines polarity for voltage reference |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered 1N52xxB series | Industry-standard part numbering and electrical validation per JEDEC JESD24 |
| ±5% voltage tolerance (B suffix) | Guaranteed VZ limits across full operating temperature range, not just at 25°C |
| Low zener impedance (8 Ω) | Minimizes output voltage variation under changing load currents in shunt regulator designs |
| Radiation hardness | Inherently hardened per MicroNote 050 - suitable for space-qualified and high-reliability systems |
| Nonsensitive to ESD | Withstands human-body-model ESD events without parameter shift (MIL-STD-750 Method 1020) |
Applications
| Power Supply Feedback | Overvoltage Clamp |
|---|---|
Use Scenario: Regulating output voltage in linear regulators or switching converter feedback paths where low-cost, fixed-voltage reference is required. IC Role / Device Role / Timing Role: Shunt voltage reference providing stable 8.2 V reference point for error amplifier input. Use Value: Enables accurate output regulation within ±5% across -65°C to +175°C without external trimming components. |
Use Scenario: Protecting sensitive inputs from transient overvoltage in sensor interfaces or microcontroller I/O lines. IC Role / Device Role / Timing Role: Bidirectional clamp limiting voltage to 8.2 V (reverse) and 1.5 V (forward) to prevent damage. Use Value: Low 3.0 μA leakage at 6.2 V ensures negligible loading on high-impedance signal paths during normal operation. |
| Precision Reference Source | Temperature-Compensated Bias |
Use Scenario: Generating stable bias voltages for op-amp circuits, ADC references, or analog front-ends in industrial instrumentation. IC Role / Device Role / Timing Role: Primary voltage reference element defining system-level accuracy and repeatability. Use Value: +0.062 %/°C tempco allows predictable drift modeling and optional passive compensation in critical analog stages. |
Use Scenario: Setting collector-emitter bias points in discrete transistor amplifiers where thermal stability is essential. IC Role / Device Role / Timing Role: Zener-based bias network compensating for transistor VBE drift with temperature. Use Value: Matches bipolar transistor thermal characteristics better than resistive dividers alone, improving gain stability. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4738A | 10% tolerance (A suffix), same 8.2 V nominal, 1 W power rating, DO-41 package | Higher power handling but larger footprint; less stable tempco (+0.085 %/°C) | Select when higher dissipation margin is needed and board space permits DO-41 mounting |
| MMBZ5237BS | SOT-23 surface-mount package, same 8.2 V ±5%, 200 mW rating, 10 Ω ZZT | Automated assembly compatible but lower power and higher impedance limit regulation accuracy | Choose for space-constrained PCBs where 500 mW is not required and reflow compatibility is mandatory |
Compared with 1N5237B, 1N4738A offers higher power but looser tolerance and different thermal profile, while MMBZ5237BS trades package size and assembly method for reduced power and regulation precision - making 1N5237B optimal for through-hole, high-stability, mid-power Zener reference use cases.
Availability
1N5237B is available at Aetrix Electronics and suitable for industrial control systems, aerospace avionics, and medical instrumentation requiring stable component supply with extended temperature capability and radiation resilience.
Supply support for 1N5237B 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-performance analog and mixed-signal components.
The 1N52xxB series was developed for military, aerospace, and industrial applications demanding guaranteed parametric performance, wide temperature operation, and long-term reliability in harsh environments.
FAQ
What is the nominal zener voltage and tolerance of the 1N5237B?
The 1N5237B has a nominal zener voltage of 8.2 V with a guaranteed tolerance of ±5%, as indicated by the "B" suffix per JEDEC specification. This tolerance is validated across the full operating temperature range (-65°C to +175°C), not just at 25°C, ensuring consistent regulation in demanding environments.
What package type and marking does the 1N5237B use?
The 1N5237B uses the DO-35 (DO-204AH) hermetically sealed glass axial-leaded package. The cathode is marked by a distinct color band on the glass body, and the full part number "1N5237B" is laser-marked or etched directly onto the device surface per manufacturer specification.
How does the 1N5237B perform under elevated temperature conditions?
The 1N5237B is rated for continuous operation from -65°C to +175°C. Its zener voltage exhibits a temperature coefficient of +0.062 %/°C, meaning voltage increases predictably with temperature - a characteristic leveraged in compensated bias networks and referenced in Microsemi's MicroNote 202 for impedance variation analysis.
Can the 1N5237B be used in surface-mount designs?
No - the 1N5237B is exclusively a through-hole axial-leaded device in DO-35 package. For surface-mount equivalents, Microsemi offers the MLL5237B in DO-213AA (MELF) package; however, that part has different thermal and mechanical characteristics and is not a drop-in replacement for 1N5237B in existing layouts.
What is the maximum reverse leakage current specified for the 1N5237B?
The 1N5237B specifies a maximum reverse leakage current (IR) of 3.0 μA at 6.2 V (80% of nominal VZ). This value is measured after 20 seconds of thermal stabilization with 3/8" lead length, ensuring reliable performance in high-impedance bias and reference circuits where leakage could affect accuracy.
1N5237B 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):
- 8.2 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)
1N5237B FAQ
1.How can I place an order for 1N5237B through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5237B 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 1N5237B reliable?
The price and inventory of 1N5237B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5237B is usually 5 days.
3.What payment methods are accepted for 1N5237B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5237B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5237B?
1N5237B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5237B 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 1N5237B?
For technical support, including 1N5237B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5237B requirements.
6.How does Aetrix verify that 1N5237B is sourced from the original manufacturer or authorized distributors?
All 1N5237B 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 1N5237B meets industry standards.
7.What is the process for return or replacement of 1N5237B?
All 1N5237B units undergo pre-shipment inspection (PSI). If there is an issue with 1N5237B, 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 1N5237B part is unused and in its original packaging.
Return procedure for 1N5237B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5237B 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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