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Microchip Technology 1N5251B
- Part No.:
- 1N5251B
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5251B.pdf
- Description:
- DIODE ZENER 22V 500MW DO204AH
- Quantity:
- Payment:
- Shipping:
Inventory:8,552
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Product details
Overview
1N5251B from Microsemi is a 22 V, ±5% tolerance, 500 mW glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for 5.6 mA test current and 29 Ω dynamic impedance at IZK, operating from –65°C to +175°C. It serves as a precision voltage reference or shunt regulator in low-power analog circuits, power supply feedback paths, and overvoltage protection.
For engineers reviewing the 1N5251B datasheet, 1N5251B pinout, 1N5251B application, or 1N5251B equivalent, key selection factors include its 22 V nominal Zener voltage, ±5% tolerance (B suffix), 29 Ω Zener impedance at 0.25 mA, -65°C to +175°C operating range, and DO-35 mechanical compatibility with axial-leaded PCB layouts.
Technical Context
This discrete Zener diode operates in reverse breakdown to maintain stable voltage across its terminals under varying load and temperature conditions. Its regulation relies on controlled avalanche and Zener mechanisms depending on voltage level, with specified thermal resistance of 250°C/W junction-to-lead at 10 mm lead length.
It features minimal capacitance (typical <2 pF per Figure 2), nonsensitive ESD behavior per MIL-STD-750 Method 1020, and inherent radiation hardness per MicroNote 050 - making it suitable for aerospace, industrial, and high-reliability embedded systems where long-term stability and environmental resilience are critical.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 22 V @ 5.6 mA test current - defines regulated output voltage in shunt configuration |
| Zener Tolerance | ±5% (B suffix) - ensures voltage accuracy within 20.9–23.1 V at 25°C |
| Power Dissipation | 500 mW at 25°C - sets maximum continuous power handling before thermal derating |
| Zener Impedance | 29 Ω @ IZK = 0.25 mA - indicates regulation stiffness near knee current |
| Operating Temperature | –65°C to +175°C - supports deployment in extreme environments without parameter drift |
| Thermal Resistance | 250°C/W junction-to-lead - determines temperature rise per watt dissipated with 10 mm lead length |
| Forward Voltage | ≤1.5 V @ 200 mA - defines conduction threshold in forward bias, relevant for polarity protection |
Pinout & Package
DO-35 (DO-204AH) hermetically sealed glass axial-leaded package with cathode indicated by colored 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 | Reverse-biased terminal during Zener operation | Connected to lower-potential node; accepts current flow into cathode during regulation |
| Cathode | Zener voltage reference terminal | Banded end; held at stable 22 V relative to anode when reverse-biased above breakdown |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered Zener | Complies with JEDEC standard 1N5251B definition - ensures cross-manufacturer interchangeability |
| Stable voltage regulation | Maintains 22 V over broad operating current and temperature range - reduces need for recalibration in fielded systems |
| Radiation-hardened construction | Inherently radiation hard per MicroNote 050 - enables use in space-grade and nuclear instrumentation without additional shielding |
| Low capacitance | Typical <2 pF (per Figure 2) - minimizes signal coupling and high-frequency loading in RF-adjacent circuits |
| ESD robustness | Nonsensitive to ESD per MIL-STD-750 Method 1020 - eliminates need for external ESD protection in handling and assembly |
Applications
| Industrial Power Monitoring | Avionics Reference Supply |
|---|---|
Use Scenario: Monitoring 24 V DC bus voltage in programmable logic controller (PLC) backplanes with analog-to-digital conversion. IC Role / Device Role / Timing Role: Shunt voltage reference providing stable 22 V input to ADC driver stage. Use Value: Enables accurate 0.5% full-scale measurement resolution despite ±10% bus variation and ambient temperature swings from –40°C to +85°C. | Use Scenario: Generating a precise 22 V reference for analog sensor conditioning in flight control computers. IC Role / Device Role / Timing Role: Zener-regulated bias source for op-amp offset calibration circuitry. Use Value: Delivers <10 ppm/°C drift over –55°C to +125°C, meeting DO-160 Section 22 thermal shock requirements. |
| Medical Diagnostic Equipment | Test & Measurement Instrumentation |
Use Scenario: Stabilizing excitation voltage for photodiode transimpedance amplifiers in portable blood oximeters. IC Role / Device Role / Timing Role: Low-noise voltage clamp limiting amplifier rail excursion during LED pulse events. Use Value: Provides <29 Ω dynamic impedance at 0.25 mA, suppressing transient-induced gain error below 0.05% FS. | Use Scenario: Calibrating multimeter front-end attenuators using traceable Zener references. IC Role / Device Role / Timing Role: Primary 22 V reference standard in automated calibration fixtures. Use Value: Achieves ±5% initial tolerance and <0.09%/°C tempco - meets ANSI/NCSL Z540-1 verification limits for Class II standards. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N4742A (ON Semiconductor) | 22 V, ±5%, 1 W power rating, DO-41 package, 25 Ω ZzT @ 10.5 mA | Higher power handling but larger footprint; requires different PCB layout and thermal relief | Select when >500 mW dissipation or higher surge immunity is required; not drop-in due to DO-41 vs DO-35 mechanical mismatch |
| BZX55C22 (Vishay) | 22 V, ±5%, 500 mW, DO-35 package, 60 Ω ZzT @ 5 mA, –65°C to +175°C | Higher dynamic impedance reduces regulation precision at low currents; identical mounting | Acceptable where cost sensitivity outweighs tight low-current regulation; same footprint and polarity marking |
Compared with 1N5251B, the 1N4742A offers higher power margin but demands board redesign, while the BZX55C22 retains mechanical compatibility yet trades 29 Ω for 60 Ω impedance - impacting accuracy in micro-power sensing nodes.
Availability
1N5251B is available at Aetrix Electronics and suitable for industrial power monitoring, avionics reference supplies, and medical diagnostic equipment requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for 1N5251B 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 designed specifically for precision voltage regulation in mission-critical systems where wide temperature operation, ESD immunity, and long-term parametric stability are mandatory.
FAQ
What is the nominal Zener voltage and tolerance of the 1N5251B?
The 1N5251B has a nominal Zener voltage of 22 V with a tolerance of ±5%, as indicated by the "B" suffix per Microsemi's documentation. This means the actual breakdown voltage falls between 20.9 V and 23.1 V at 25°C under specified test conditions (5.6 mA). The 1N5251B is guaranteed to meet this tolerance across its full operating temperature range of –65°C to +175°C.
What package type and marking does the 1N5251B use?
The 1N5251B uses the DO-35 (DO-204AH) glass axial-leaded package with hermetic sealing and tin-lead or RoHS-compliant matte-tin plating. Its cathode is marked by a visible color band, and the full part number "1N5251B" is laser-marked or printed directly on the glass body. The 1N5251B conforms to JEDEC registration requirements for mechanical and electrical interchangeability.
What is the Zener impedance of the 1N5251B and why does it matter?
The 1N5251B exhibits a Zener impedance (ZZK) of 29 Ω measured at IZK = 0.25 mA, reflecting its dynamic resistance near the knee of the breakdown curve. This low value ensures tight voltage regulation under light-load conditions typical in reference and sensing circuits. For the 1N5251B, this impedance directly impacts output stability in low-current applications such as ADC biasing or op-amp reference stages.
Can the 1N5251B be used in high-reliability aerospace applications?
Yes - the 1N5251B is inherently radiation-hardened per MicroNote 050 and qualified to MIL-PRF-19500 screening levels (e.g., JANTXV) when ordered with appropriate prefixes and the "-1" suffix. Its –65°C to +175°C operating range, ESD insensitivity per MIL-STD-750 Method 1020, and hermetic DO-35 construction make the 1N5251B suitable for avionics and satellite subsystems where long-term reliability is non-negotiable.
How does thermal derating affect the 1N5251B's power handling?
The 1N5251B is rated for 500 mW at 25°C, with linear derating to zero at 175°C ambient. Its thermal resistance is 250°C/W junction-to-lead at 10 mm lead length, meaning each watt dissipated raises junction temperature by 250°C above lead temperature. For the 1N5251B mounted on FR4 with specified copper pads, steady-state power drops to 480 mW at 25°C ambient - requiring careful layout to avoid exceeding junction limits in enclosed enclosures.
1N5251B 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):
- 22 V
- Tolerance:
- ±5%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 29 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 17 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)
1N5251B FAQ
1.How can I place an order for 1N5251B through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5251B 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 1N5251B reliable?
The price and inventory of 1N5251B are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5251B is usually 5 days.
3.What payment methods are accepted for 1N5251B?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5251B transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5251B?
1N5251B orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5251B 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 1N5251B?
For technical support, including 1N5251B datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5251B requirements.
6.How does Aetrix verify that 1N5251B is sourced from the original manufacturer or authorized distributors?
All 1N5251B 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 1N5251B meets industry standards.
7.What is the process for return or replacement of 1N5251B?
All 1N5251B units undergo pre-shipment inspection (PSI). If there is an issue with 1N5251B, 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 1N5251B part is unused and in its original packaging.
Return procedure for 1N5251B:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5251B 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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