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Microchip Technology 1N5256A
- Part No.:
- 1N5256A
- Manufacturer:
- Microchip Technology
- Category:
- Single Zener Diodes
- Package:
- DO-204AH, DO-35, Axial
- Datasheet:
-
1N5256A.pdf
- Description:
- DIODE ZENER 30V 500MW DO204AH
- Quantity:
- Payment:
- Shipping:
Inventory:5,951
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Product details
Overview
1N5256A from Microsemi is a 30 V, ±10% tolerance, 500 mW glass axial-lead Zener diode in DO-35 (DO-204AH) package, rated for 49 Ω zener impedance at 0.25 mA and 22 V maximum zener voltage at 10 mA test current, used for precision low-power voltage regulation in power supply reference circuits.
For engineers reviewing the 1N5256A datasheet, 1N5256A pinout, 1N5256A application, or 1N5256A equivalent, this page delivers verified electrical specs, thermal derating behavior, temperature coefficient (+0.091 %/°C), cathode-band polarity marking, and RoHS-compliant plating options - all critical for stable biasing and reference design in industrial analog systems.
Technical Context
The 1N5256A operates as a two-terminal voltage reference device with sharp reverse breakdown knee, characterized by 49 Ω dynamic impedance at IZK = 0.25 mA and 22 Ω at IZT = 10 mA. Its zener voltage exhibits +0.091 %/°C temperature coefficient over −65°C to +175°C operating range.
It is constructed in a hermetically sealed DO-35 glass package with tin-lead or RoHS-compliant matte-tin plating, rated for 0.5 W steady-state dissipation at TL < 50°C (3/8″ lead length) and derated linearly above that point per Figure 1.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Nominal Zener Voltage | 30 V @ IZT = 10 mA - defines primary regulation setpoint under standard test conditions |
| Zener Tolerance | ±10% (A suffix) - guarantees actual VZ between 27 V and 33 V at 25°C |
| Zener Impedance | 49 Ω @ IZK = 0.25 mA - indicates low dynamic resistance near knee, enabling stable low-current regulation |
| Power Dissipation | 500 mW at 25°C ambient - sets absolute max continuous DC power before thermal derating applies |
| Operating Temperature | −65°C to +175°C - supports deployment in extended industrial, aerospace, and downhole environments |
| Thermal Resistance | 250 °C/W junction-to-lead (3/8″ lead length) - enables accurate junction temperature estimation for reliability analysis |
| Forward Voltage | ≤1.5 V @ 200 mA - ensures predictable forward conduction if accidentally biased in forward direction |
Pinout & Package
DO-35 (DO-204AH) glass axial-leaded package with cathode indicated by single black band; leads are flexible axial terminals suitable for through-hole mounting on FR4 PCBs with 1 mm track width and 4 mm² copper pads.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Non-banded end | Connected to lower-potential node; must be negative relative to cathode for Zener operation |
| Cathode | Banded end | Connected to higher-potential node; reverse-biased terminal where regulated voltage appears |
Key Features
| Feature | Design Value |
|---|---|
| JEDEC-registered DO-35 construction | Ensures mechanical and electrical interchangeability across qualified suppliers and legacy designs |
| RoHS-compliant option (e3 suffix) | Enables compliance with environmental directives without sacrificing electrical performance or thermal rating |
| Low capacitance (typ. <2 pF) | Minimizes high-frequency loading in timing, oscillator, and RF bias networks |
| Radiation-hardened per MicroNote 050 | Validated for use in space-grade and nuclear instrumentation applications requiring TID tolerance |
| Nonsensitive to ESD (MIL-STD-750 Method 1020) | Eliminates need for handling precautions during assembly, reducing manufacturing risk |
Applications
| Low-Power Reference Supply | Overvoltage Clamp Circuit |
|---|---|
Use Scenario: Providing stable 30 V reference for op-amp biasing and ADC voltage references in battery-powered sensor nodes. IC Role / Device Role / Timing Role: Two-terminal passive voltage reference establishing fixed potential independent of load current variation. Use Value: Delivers ±10% regulation accuracy with 49 Ω dynamic impedance, enabling sub-1% reference stability when combined with low-noise filtering. |
Use Scenario: Protecting microcontroller I/O pins from transient surges exceeding 33 V in industrial control inputs. IC Role / Device Role / Timing Role: Shunt clamping element diverting excess energy to ground once input exceeds 30 V nominal breakdown. Use Value: Limits peak voltage to ≤33 V with fast response (<10 ns), leveraging low junction capacitance and robust 175°C operating limit. |
| Temperature-Stable Bias Network | Legacy Analog Instrument Calibration |
Use Scenario: Setting collector bias in discrete transistor amplifiers requiring minimal drift across −40°C to +85°C ambient. IC Role / Device Role / Timing Role: Precision voltage source compensating for transistor VBE shift via matched thermal coupling. Use Value: +0.091 %/°C tempco enables predictable, linear drift correction - critical for 0.1% gain stability in measurement front-ends. |
Use Scenario: Replacing obsolete 30 V Zeners in calibrated multimeters and oscilloscope attenuator stages. IC Role / Device Role / Timing Role: Drop-in replacement for legacy 1N5256-type references requiring JEDEC DO-35 form factor and 30 V nominal rating. Use Value: Maintains identical mechanical footprint, polarity marking, and thermal derating curve - no board rework required. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5256B | ±5% tolerance (vs. ±10% for 1N5256A); otherwise identical VZ, ZZT, and thermal specs | Used where tighter regulation accuracy is required without changing layout or thermal design | Select 1N5256B when system-level voltage error budget demands <±0.5 V deviation at 30 V nominal |
| MMBZ5256B (SOT-23) | Surface-mount MMBZ5256B offers same 30 V ±5%, but in SOT-23 package with 350 mW rating and higher thermal resistance | Suitable for space-constrained PCBs where axial DO-35 leads are incompatible with automated placement | Choose MMBZ5256B only when board real estate or assembly process mandates SMT; verify derating for 350 mW limit |
Compared with 1N5256A, the 1N5256B improves regulation accuracy without altering thermal or mechanical interface, while MMBZ5256B trades package compatibility and power rating for surface-mount integration - neither is pin-compatible, but both serve overlapping voltage-reference roles.
Availability
1N5256A is available at Aetrix Electronics and suitable for low-power reference supplies, overvoltage protection circuits, and temperature-stable bias networks requiring stable component supply and long-term obsolescence management.
Supply support for 1N5256A 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, RF, and radiation-hardened components for aerospace, defense, and industrial markets.
The 1N52xx series was designed specifically for precision, low-power voltage regulation in mission-critical analog subsystems where long-term stability, wide temperature operation, and JEDEC-standard interoperability are mandatory.
FAQ
What is the nominal zener voltage and tolerance of the 1N5256A?
The 1N5256A has a nominal zener voltage of 30 V with a ±10% tolerance, meaning its actual breakdown voltage falls between 27 V and 33 V at 25°C when tested at 10 mA. This tolerance is confirmed by the "A" suffix per Microsemi's documentation and applies across the full operating temperature range.
What package type and marking does the 1N5256A use?
The 1N5256A uses the DO-35 (DO-204AH) glass axial-leaded package with a single black cathode band on the banded end. The part number "1N5256A" is laser-marked or etched directly onto the glass body, consistent with JEDEC registration requirements for the 1N52xx family.
How does the 1N5256A perform under elevated temperature conditions?
The 1N5256A maintains operation from −65°C to +175°C with a +0.091 %/°C temperature coefficient. Its power dissipation derates linearly above 50°C lead temperature, reaching zero at 175°C - a behavior documented in Figure 1 of the Microsemi datasheet and validated for high-reliability thermal cycling.
Is the 1N5256A RoHS compliant?
Yes - the 1N5256A is available in RoHS-compliant form with the "e3" suffix (e.g., 1N5256Ae3), featuring annealed matte-tin plating per MIL-STD-750 Method 2026. Standard versions use tin-lead plating, and both share identical electrical and thermal specifications.
What is the maximum zener impedance of the 1N5256A and at what condition is it specified?
The 1N5256A has a maximum zener impedance of 49 Ω, measured at IZK = 0.25 mA using 60 Hz AC superimposed on DC bias - a method defined in Note 2 of the Microsemi datasheet to ensure sharp knee characterization and eliminate unstable units.
1N5256A 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):
- 30 V
- Tolerance:
- ±10%
- Power - Max:
- 500 mW
- Impedance (Max) (Zzt):
- 49 Ohms
- Current - Reverse Leakage @ Vr:
- 100 nA @ 22 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)
1N5256A FAQ
1.How can I place an order for 1N5256A through Aetrix?
Please submit a Request for Quotation (RFQ) for 1N5256A 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 1N5256A reliable?
The price and inventory of 1N5256A are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1N5256A is usually 5 days.
3.What payment methods are accepted for 1N5256A?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1N5256A transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1N5256A?
1N5256A orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1N5256A 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 1N5256A?
For technical support, including 1N5256A datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1N5256A requirements.
6.How does Aetrix verify that 1N5256A is sourced from the original manufacturer or authorized distributors?
All 1N5256A 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 1N5256A meets industry standards.
7.What is the process for return or replacement of 1N5256A?
All 1N5256A units undergo pre-shipment inspection (PSI). If there is an issue with 1N5256A, 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 1N5256A part is unused and in its original packaging.
Return procedure for 1N5256A:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1N5256A Tags
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MMBZ5240B-7-F
Diodes Incorporated
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